I ran into this exact same issue I am experiencing now about 2 months ago and it literally makes no sense. I have an ID field in my two entities that are type autonumber (my PK's).
When I am using my app I previously had an edit form for each entity and hid the ID field and like magic, the PK field would automatically create a unique ID using a seed...... but now.... because I had to redo my fields, I am back to the exact same predicament I was in 2 months ago where autonumber is just failing to work.
Microsofts documentation literally make it sound like whenever a new row is added then this column will be filled out and incremented by one, which is exactly what was happening for the past few weeks, but now it is just submitting nothing. Please help!! I solved this two months ago by literally just mass submitting rows until it started working consistantly. It has never made sense to me.
