I recently experienced a frustrating issue that had me scratching my head for a while. I had a PO form with a Line Item subform and I could edit lines and when I tried to delete a line it was removed from the subform.

BUT… If I closed and reopened the same PO record, the deleted line was there again.

I tracked this down to having changed the recordsource property of the subform to use a query that I joined with another grouped query to pull in a data field I needed to display.

When I reverted the recordsource back to the underlying table, it worked again.

Instead of pulling the data in by joining it in the recordsource query, I ended up just creating another query in vba when the subform opened and searching against that for the data I needed in the OnCurrent event of the subform.