diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
new file mode 100644
index 0000000..fd5d17f
--- /dev/null
+++ b/.github/workflows/deploy.yml
@@ -0,0 +1,84 @@
+name: Deploy
+
+on:
+ release:
+    types:
+      - created
+
+jobs:
+
+
+ ########################################################################################
+  checkout:
+    name: Checkout
+    strategy:
+      matrix:
+        machine: [x64_linux, x64_mac, arm64_linux, arm64_mac]
+    runs-on: [self-hosted, kmer-db, '${{ matrix.machine }}']
+    
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+########################################################################################
+  make:
+    name: Make
+    needs: checkout
+    strategy:
+      fail-fast: false
+      matrix:
+        machine: [x64_linux]
+        platform: [avx2]
+        compiler: [g++-13]
+        static: [true]
+        include:
+        - {machine: arm64_linux, platform: arm8, compiler: g++-12, static: true}
+        - {machine: x64_mac, platform: avx2, compiler: g++-13, static: false}
+        - {machine: arm64_mac, platform: m1, compiler: g++-13, static: false}
+       
+    runs-on: [self-hosted, famsa, '${{ matrix.machine }}']  
+        
+    steps:
+    - name: make 
+      run: |
+        make clean
+        make -j32 CXX=${{matrix.compiler}} STATIC_LINK=${{ matrix.static }} PLATFORM=${{ matrix.platform }}
+    - name: tar artifacts
+      run: tar -cvzf famsa.tar.gz famsa LICENSE
+
+      
+########################################################################################
+  help:
+    name: Print usage
+    needs: make
+    strategy:
+      fail-fast: false
+      matrix:
+        machine: [x64_linux, x64_mac, arm64_linux, arm64_mac]
+    runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
+        
+    steps:
+    - name: help
+      run: ./famsa
+
+########################################################################################
+  upload:
+    name: Upload
+    needs: help
+    strategy:
+      fail-fast: false
+      matrix:
+        machine: [x64_linux, x64_mac, arm64_linux, arm64_mac]
+    runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
+    
+    steps:
+    - name: deploy
+      uses: actions/upload-release-asset@v1.0.1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        upload_url: ${{ github.event.release.upload_url }}
+        asset_path: ./famsa.tar.gz
+        asset_name: famsa-${{ github.event.release.tag_name }}-${{matrix.machine}}.tar.gz
+        asset_content_type: application/gzip
diff --git a/.github/workflows/self-hosted.yml b/.github/workflows/self-hosted.yml
index f2d7346..05ad55b 100644
--- a/.github/workflows/self-hosted.yml
+++ b/.github/workflows/self-hosted.yml
@@ -15,7 +15,7 @@ jobs:
     name: checkout
     strategy:
       matrix:
-        machine: [xeon, tripper, raspberry, mac-m1, mac-i7]
+        machine: [xeon, x64_linux, x64_mac, arm64_linux, arm64_mac]
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
     
     steps:
@@ -37,36 +37,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # multiple X64 configurations
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-10, g++-11]
+        machine: [x64_linux]
+        compiler: [g++-9, g++-10, g++-11, g++-12, g++]
         platform: [avx2]
-        # additional ARM configurations
         include:
-        - machine: raspberry
-          compiler: g++
-          platform: arm8
-          
-        - machine: mac-m1
-          compiler: g++
-          platform: m1
-        - machine: mac-i7
-          compiler: g++
-          platform: avx2
-          
-#        - machine: old
-#          compiler: g++-5
-#          platform: avx2
-#        - machine: old
-#          compiler: g++-6
-#          platform: avx2
-#        - machine: old
-#          compiler: g++-7
-#          platform: avx2
-#        - machine: old
-#          compiler: g++-8
-#          platform: avx2
- 
+        - {machine: xeon, platform: avx2, compiler: g++}
+        - {machine: arm64_linux, platform: arm8, compiler: g++}
+        - {machine: x64_mac, platform: avx2, compiler: g++}
+        - {machine: arm64_mac, platform: m1, compiler: g++}
+
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
 
     steps:
@@ -85,17 +64,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-10, g++-11]
-        # additional ARM configurations
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         include:
-        - machine: raspberry
-          compiler: g++
-          
-        - machine: mac-m1
-          compiler: g++
-        - machine: mac-i7
-          compiler: g++
+        - {machine: x64_linux, compiler: g++-9}
+        - {machine: x64_linux, compiler: g++-10}
+        - {machine: x64_linux, compiler: g++-11}
+        - {machine: x64_linux, compiler: g++-12}
      
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']    
     
@@ -133,54 +108,19 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-10, g++-11]
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         tree: [sl, upgma, slink]
-        # additional ARM configurations
         include:
-        - machine: raspberry
-          compiler: g++
-          tree: sl
-        - machine: raspberry
-          compiler: g++
-          tree: upgma
-        - machine: raspberry
-          compiler: g++
-          tree: slink
-
-        - machine: mac-m1
-          compiler: g++
-          tree: sl
-        - machine: mac-m1
-          compiler: g++
-          tree: upgma
-        - machine: mac-m1
-          compiler: g++
-          tree: slink
-
-        - machine: mac-i7
-          compiler: g++
-          tree: sl
-        - machine: mac-i7
-          compiler: g++
-          tree: upgma
-        - machine: mac-i7
-          compiler: g++
-          tree: slink
-   
-#        - machine: old
-#          compiler: g++-5
-#          tree: sl
-#        - machine: old
-#          compiler: g++-6
-#          tree: sl
-#        - machine: old
-#          compiler: g++-7
-#          tree: sl
-#        - machine: old
-#          compiler: g++-8
-#          tree: sl
-          
+        - {machine: x64_linux, compiler: g++-9, tree: sl}
+        - {machine: x64_linux, compiler: g++-9, tree: upgma}
+        - {machine: x64_linux, compiler: g++-10, tree: sl}
+        - {machine: x64_linux, compiler: g++-10, tree: upgma}
+        - {machine: x64_linux, compiler: g++-11, tree: sl}
+        - {machine: x64_linux, compiler: g++-11, tree: upgma}
+        - {machine: x64_linux, compiler: g++-12, tree: sl}
+        - {machine: x64_linux, compiler: g++-12, tree: upgma}
+        
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
         
     env: 
@@ -218,22 +158,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-11]
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         tree: [sl]
-        # additional ARM configurations
         include:
-        - machine: raspberry
-          compiler: g++
-          tree: sl
-          
-        - machine: mac-m1
-          compiler: g++
-          tree: sl
-        - machine: mac-i7
-          compiler: g++
-          tree: sl
-     
+        - {machine: x64_linux, compiler: g++-9, tree: sl}
+        - {machine: x64_linux, compiler: g++-10, tree: sl}
+        - {machine: x64_linux, compiler: g++-11, tree: sl}
+        - {machine: x64_linux, compiler: g++-12, tree: sl}
+       
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
         
     env: 
@@ -265,50 +198,23 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-10, g++-11]
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         tree: [sl, upgma, slink, nj]
-        # additional ARM configurations
         include:
-        - machine: raspberry
-          compiler: g++
-          tree: sl
-        - machine: raspberry
-          compiler: g++
-          tree: upgma
-        - machine: raspberry
-          compiler: g++
-          tree: slink
-        - machine: raspberry
-          compiler: g++
-          tree: nj
-          
-        - machine: mac-m1
-          compiler: g++
-          tree: sl
-        - machine: mac-m1
-          compiler: g++
-          tree: upgma
-        - machine: mac-m1
-          compiler: g++
-          tree: slink
-        - machine: mac-m1
-          compiler: g++
-          tree: nj
-        
-        - machine: mac-i7
-          compiler: g++
-          tree: sl
-        - machine: mac-i7
-          compiler: g++
-          tree: upgma
-        - machine: mac-i7
-          compiler: g++
-          tree: slink
-        - machine: mac-i7
-          compiler: g++
-          tree: nj  
-          
+        - {machine: x64_linux, compiler: g++-9, tree: sl}
+        - {machine: x64_linux, compiler: g++-9, tree: upgma}
+        - {machine: x64_linux, compiler: g++-9, tree: nj}
+        - {machine: x64_linux, compiler: g++-10, tree: sl}
+        - {machine: x64_linux, compiler: g++-10, tree: upgma}
+        - {machine: x64_linux, compiler: g++-10, tree: nj}
+        - {machine: x64_linux, compiler: g++-11, tree: sl}
+        - {machine: x64_linux, compiler: g++-11, tree: upgma}
+        - {machine: x64_linux, compiler: g++-11, tree: nj}
+        - {machine: x64_linux, compiler: g++-12, tree: sl}
+        - {machine: x64_linux, compiler: g++-12, tree: upgma}
+        - {machine: x64_linux, compiler: g++-12, tree: nj}
+
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
       
     env: 
@@ -345,21 +251,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-11]
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         tree: [sl]
-        # additional ARM configurations
         include:
-        - machine: raspberry
-          compiler: g++
-          tree: sl
-        
-        - machine: mac-m1
-          compiler: g++
-          tree: sl
-        - machine: mac-i7
-          compiler: g++
-          tree: sl
+        - {machine: x64_linux, compiler: g++-9, tree: sl}
+        - {machine: x64_linux, compiler: g++-10, tree: sl}
+        - {machine: x64_linux, compiler: g++-11, tree: sl}
+        - {machine: x64_linux, compiler: g++-12, tree: sl}
      
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']
         
@@ -408,17 +307,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-10, g++-11]
-        # additional ARM configurations
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         include:
-        - machine: raspberry
-          compiler: g++
-          
-        - machine: mac-m1
-          compiler: g++
-        - machine: mac-i7
-          compiler: g++
+        - {machine: x64_linux,  compiler: g++-9}
+        - {machine: x64_linux, compiler: g++-10}
+        - {machine: x64_linux, compiler: g++-11}
+        - {machine: x64_linux, compiler: g++-12}
      
     runs-on: [self-hosted, famsa, '${{ matrix.machine }}']    
         
@@ -476,12 +371,12 @@ jobs:
 ########################################################################################
   noavx-tests:
     name: distances only - different TRipper SIMD extensions 
-    runs-on: [self-hosted, famsa, tripper]
+    runs-on: [self-hosted, famsa, x64_linux]
     needs: small-tests
     strategy:
       fail-fast: false
       matrix:
-        compiler: [g++-9, g++-10, g++-11]
+        compiler: [g++-9, g++-10, g++-11, g++-12, g++-13]
         platform: [none, sse4, avx]
         
     env: 
@@ -507,17 +402,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        machine: [xeon, tripper]
-        compiler: [g++-9, g++-11]
+        machine: [xeon, x64_linux, arm64_linux, x64_mac, arm64_mac]
+        compiler: [g++]
         tree: [sl]
-        
         include:
-        - machine: mac-m1
-          compiler: g++
-          tree: sl
-        - machine: mac-i7
-          compiler: g++
-          tree: sl 
+        - {machine: x64_linux, compiler: g++-9, tree: sl}
+        - {machine: x64_linux, compiler: g++-10, tree: sl}
+        - {machine: x64_linux, compiler: g++-11, tree: sl}
+        - {machine: x64_linux, compiler: g++-12, tree: sl}
           
     env: 
       REF_DIR: ./test/LRR
diff --git a/makefile b/makefile
index 9dc1fca..5760010 100644
--- a/makefile
+++ b/makefile
@@ -116,7 +116,7 @@ INCLUDES=$(foreach d, $(INC_DIRS), -I$d)
  
 ifeq ($(STATIC_LINK), true) 
 	CXXFLAGS	= -Wall -Wno-char-subscripts -Wno-attributes -O3 $(COMMON_FLAGS) $(DEFINE_FLAGS) -static -Wl,--whole-archive -lpthread -Wl,--no-whole-archive -std=$(CPP_STD) $(INCLUDES)
-	CLINK	= -lm -static -O3 -msse4 -Wl,--whole-archive -lpthread -Wl,--no-whole-archive -std=$(CPP_STD)
+	CLINK	= -lm -static -O3 -Wl,--whole-archive -lpthread -Wl,--no-whole-archive -std=$(CPP_STD)
 else
 	CXXFLAGS	= -Wall -Wno-char-subscripts -Wno-attributes -O3 $(COMMON_FLAGS) $(DEFINE_FLAGS) -std=$(CPP_STD) -pthread $(INCLUDES)
 	CLINK	= -lm $(CLINK_FLAGS) -O3 $(COMMON_FLAGS) -std=$(CPP_STD) -pthread 
diff --git a/src/core/sequence.cpp b/src/core/sequence.cpp
index 683dfc7..54401be 100644
--- a/src/core/sequence.cpp
+++ b/src/core/sequence.cpp
@@ -231,6 +231,7 @@ CGappedSequence::CGappedSequence(const string& _id, const string& seq, int seq_n
 			symbols=(symbol_t*)mma->allocate(symbols_size + 1);}
 		else {
 			symbols=new symbol_t[symbols_size +1];}
+                symbols[0]=GUARD;
 	}
 	else {
 		symbols=nullptr;
@@ -255,10 +256,10 @@ CGappedSequence::CGappedSequence(const string& _id, const string& seq, int seq_n
 			char* q = find(mapping_table, mapping_table + 25, c);
 			if (q == mapping_table + 25) {
 				extra_symbols.emplace_back(is, c); // save non-standard symbol
-				symbols[is] = (symbol_t)UNKNOWN_SYMBOL;
+				symbols[is+1] = (symbol_t)UNKNOWN_SYMBOL;
 			}
 			else {
-				symbols[is] = (symbol_t)(q - mapping_table);
+				symbols[is+1] = (symbol_t)(q - mapping_table);
 			}
 
 			++is;
@@ -313,7 +314,7 @@ CGappedSequence::CGappedSequence(const CGappedSequence& _gapped_sequence) :
 		symbols = new symbol_t[symbols_size + 1];
 
 	
-	copy_n(_gapped_sequence.symbols, symbols_size, symbols);
+	copy_n(_gapped_sequence.symbols, symbols_size + 1, symbols);
 
 	n_gaps = _gapped_sequence.n_gaps;
 	dps = _gapped_sequence.dps;
diff --git a/src/core/version.h b/src/core/version.h
index eab6d1d..2c237a9 100644
--- a/src/core/version.h
+++ b/src/core/version.h
@@ -9,14 +9,17 @@ Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Adam Gudys
 #ifndef _VERSION_H
 #define _VERSION_H
 
-#define FAMSA_VER		"2.2.2"
-#define FAMSA_DATE		"2022-10-09"
+#define FAMSA_VER		"2.2.3"
+#define FAMSA_DATE		"2024-09-17"
 #define FAMSA_AUTHORS	"S. Deorowicz, A. Debudaj-Grabysz, A. Gudys"
 
 #endif
 
 /*
 Version history:
+2.2.3 (2024-09-17):
+- Fixed rare bug in single linkage when analyzing sequences with zero similarity. Release deployment scripts added.
+
 2.2.2 (2022-10-09):
 - Fixed slowdown caused by the duplicate removal (feature added in 2.1.0).