diff --git a/x/stake/cross_stake/cross_stake.go b/x/stake/cross_stake/cross_stake.go
index 06d4cebfb..6bbd43460 100644
--- a/x/stake/cross_stake/cross_stake.go
+++ b/x/stake/cross_stake/cross_stake.go
@@ -227,19 +227,9 @@ func (app *CrossStakeApp) handleUndelegate(ctx sdk.Context, pack *types.CrossSta
 		}, errCode, nil
 	}
 
-	if sdk.IsUpgrade(sdk.FirstSunsetFork) {
-		// unbound the delegation directly, do not wait for the breathe block
-		// this is to prevent too many user get the coins back in the breathe block
-
-		_, _, err := app.stakeKeeper.UnboundDelegation(ctx.WithCrossStake(true), delAddr, pack.Validator, shares)
-		if err != nil {
-			return sdk.ExecuteResult{}, errCode, err
-		}
-	} else {
-		_, err := app.stakeKeeper.BeginUnbonding(ctx.WithCrossStake(true), delAddr, pack.Validator, shares, true)
-		if err != nil {
-			return sdk.ExecuteResult{}, errCode, err
-		}
+	_, err := app.stakeKeeper.BeginUnbonding(ctx.WithCrossStake(true), delAddr, pack.Validator, shares, true)
+	if err != nil {
+		return sdk.ExecuteResult{}, errCode, err
 	}
 
 	// publish undelegate event
diff --git a/x/stake/endblock.go b/x/stake/endblock.go
index 22611e940..c0342311d 100644
--- a/x/stake/endblock.go
+++ b/x/stake/endblock.go
@@ -46,6 +46,15 @@ func EndBlocker(ctx sdk.Context, k keeper.Keeper) (validatorUpdates []abci.Valid
 		}
 	}
 
+	if len(storePrefixes) > 0 && sdk.IsUpgrade(sdk.FirstSunsetFork) {
+		for i := range storePrefixes {
+			sideChainCtx := ctx.WithSideChainKeyPrefix(storePrefixes[i])
+			_, unBoundedEvents := handleMatureUnbondingDelegations(k, sideChainCtx)
+
+			events = append(events, unBoundedEvents...)
+		}
+	}
+
 	if sdk.IsUpgrade(sdk.BEP153) {
 		events = events.AppendEvents(csEvents)
 	}
diff --git a/x/stake/handler_sidechain.go b/x/stake/handler_sidechain.go
index 2b4582e0f..a073b7fa6 100644
--- a/x/stake/handler_sidechain.go
+++ b/x/stake/handler_sidechain.go
@@ -442,19 +442,9 @@ func handleMsgSideChainUndelegate(ctx sdk.Context, msg MsgSideChainUndelegate, k
 		events sdk.Events
 	)
 
-	if sdk.IsUpgrade(sdk.FirstSunsetFork) {
-		// unbound the delegation directly, do not wait for the breathe block
-		// this is to prevent too many user get the coins back in the breathe block
-
-		ubd, events, err = k.UnboundDelegation(ctx, msg.DelegatorAddr, msg.ValidatorAddr, shares)
-		if err != nil {
-			return err.Result()
-		}
-	} else {
-		ubd, err = k.BeginUnbonding(ctx, msg.DelegatorAddr, msg.ValidatorAddr, shares, true)
-		if err != nil {
-			return err.Result()
-		}
+	ubd, err = k.BeginUnbonding(ctx, msg.DelegatorAddr, msg.ValidatorAddr, shares, true)
+	if err != nil {
+		return err.Result()
 	}
 
 	finishTime := types.MsgCdc.MustMarshalBinaryLengthPrefixed(ubd.MinTime)