A form should keep your work when saving fails

An error toast is not a recovery experience if the form clears itself. I would retain edits, mark the fields affected by validation, and give uncertain network failures a different message from rejected content. Successful saves should have a visible persisted result.

Associate validation messages with their controls and move focus only when that helps the user locate the problem. An announcement alone can be easy to miss in a long form.

Avoid retrying a changed form with the previous write identity. The old request and the edited request express different intentions; keep each operation paired with its exact payload.