Per our conversation, you have a DK-RC-BAC-1 unit that is connected with a EASY IO FG20+ PLC unit. You are experiencing issues with the PLC, that when it sends a set temp command the temp does not update.
However, this commands send no problem from the HMI and remote.
Can you please supply the dipswitch summary? I will reach to SPain for some additional guiddance on the issue.