'Deleted' draft email keeps re-appearing. Why??

It's really weird, and kind of annoying. I have a draft email from last year that keeps popping up whenever I open yahoo mail. My drafts folder is empty. When I click on the trash can icon for this annoying come-back-email, it asks for verification, I click on yes, please delete, and it goes away. However, the next time I come back to Yahoo mail, there is that same draft email--like a ghost that won't go away.
Why? Anyone!
BTW, I have three browsers that I use depending on the circumstances. Opera, Edge, and Chrome. Doesn't matter which one I use, the draft keeps popping back after a verified deletion.

Windows / Opera 87.0.4390.45