Perhaps it’s possible that the write is failing the first time because the OPC subscription has not fully initialized. This is unlikely, but is the only thing that comes to mind.
What are your trigger settings exactly? Are you only using the “only evalutate this group…(async)” option, or do you have an actual trigger- such as an action item that reads some field from the database?
If you’re only using the async mode, it may work better to have a separate trigger table/column in the database that is read by an action item. Then you can execute on change, but use the “prevent trigger caused by group start” option to avoid the first execution.
Regards,