I confirm, that this is reproducible reliably in the latest release. I have a few infos to add:
- This even happens for me if the draft e-mail has some content
- The thread where tha draft e-mail is deleted is displayed in the Trash, whereas the draft e-mail seems to be completely deleted and does not appear in the thread that is displayed in the Trash
- Cleaning the mailsync cache deletes the thread from the view in the Trash
The commands that are sent from the UI to the Mailsync Engine seem correct. Therefore this looks like it needs to be resolved inside the sync engine.