select ST_GeomFromGeoJSON('{
      "type": "Point",
      "coordinates": [30.0, 10.0]}') as p;

with DuckDB-1.2:

POINT (30 10)

with DuckDB-1.3.1.0:

DuckDBBlobResult{buffer=java.nio.HeapByteBuffer[pos=0 lim=32 cap=32]}

Of course I can cast to text explicitly but I believe the JDBC driver should map GEOMETRY to TEXT instead of BLOB.
Or at least let ResultSet.getString() return the proper TEXT when typeOf is GEOMETRY.