Bidirectional Transaction Groups Don't Update Null Date Values From DB

I have set up a standard transaction group and configured a DateTime item to use bi-directional mode. The idea is that I can update values from either the DB or the tag and the other side will update as well. However, every time I put in a null value in either the tag or the DB, it gets rejected and written back to what it was. It works well with non-null values. Does anyone know how to make it work? I am using V8.1.22

Hello zzeng2,

Does that column in the database table have the Not-Null constraint configured? This would cause the NULL values to be rejected by the database. Could you also check to see if you have the transaction group configured to set NULL values back to default values in the Options tab?

Thanks for replying. I did check the database and made sure the column is nullable. These options you mentioned are not checked in the transaction group. If it helps, I am running MySQL 8.0.15.

What's interesting is if I just use OPC to DB or DB to OPC one directional mode, null values are properly updated.