I had the same problem and I was only able to resolve it by publishing a new survey with a different name (apart from all the work of recovering old data, repointing webmaps, dashboards, etc.).
Below is the history of the problem and the tests I carried out:
1 - Initially, opening the field app through the URL gave an error, while opening the application directly through Windows worked. To correct the error, simply close and open the field app again and send the records from the Outbox;
2 - At a certain point, opening directly through Windows also started to give an error;
3 - I removed the submission_url from the form and, even pointing to the "original" layer, the error persisted (both opening via link and via Windows);
4 - I created a new form, with a different name, pointing to the "original" visualization layer (through submission_url) and the error persisted (both opening via link and via Windows);
5 - Finally, I decided to publish a new search and a new layer and, for now, it stopped giving errors (it works by opening the form via link and through Windows)
Update: after creating a view of the new layer and pointing it to the submission_url, the problem returned 🙄
