As part of the draft migration, UI fetches drafts from both the user store and the backend. When a user saves a draft it is only saved to the backend and deleted from the user store (if thats where it came from). This ensures we eventually migrate all drafts to the new system.
The UI deletes the draft from the user store even if the request to save to the backend fails. This occurs when the pipeline studio service in the backend is unavailable. The correct behavior would be to fall-back to the user store (either save to user store or at least not delete) if the studio service is down.
Steps to reproduce in 6.3.0:
1. Save a draft into the user store
2. Stop the studio service in the backend
3. Open and attempt to save the draft, the save will fail.
4. Go back to the list page and notice that the draft was deleted