I did already find you block and seems to be similar but as you say without the RCSI part. There are some temporary table DDL included as the merge are between the temp table and the target table. The target table do have one non-clustered index but the dead lock is on the PK index.I did already find you block and seems to be similar but as you say without the RCSI part. There are some temporary table DDL included as the merge are between the temp table and the target table. The target table do have one non-clustered index but the dead lock is on the PK index.

Are you getting actual deadlocks (msg 1205) or update conflicts (msg 3960)?