I had the excact problem - not able to edit records even though previously everything worked well. I tried recommended above step - checking excel code for duplicates. It turned out we had a few. I redeployed form without name duplicates and everything works correctly now! I am able to edit records. Fortunately, the impacted questions weren’t filled in massively. Otherwise - all answers to impacted questions would disappear (be careful!!!).
I suppose it must have been some problem when Kobo at all allowed to deploy form with name duplicates. Previously it would have said, that it can’t be deployed because of errors. So now we are facing consequences…
