What error message do you get? WE only know what you tell us.

I have the same issue. Every time I save to drafts is see a momentary popup which appears to be a progress indicator but there is no sign of it in the Drafts folder. In addition, if I edit an existing draft it is deleted when I click save. The Activity Manager says a file has been deleted but it isn't in Trash or Junk folders. I have version 102.6.1 (64 bit).

Just found my Draft emails. They had been moved into "Local folders" for some reason, even though I was sending them from my main email.