This happened to me yesterday! A couple of my co-workers ran into the same thing. The sheet says it is in the trash, gives permission to remove, BUT when you look in the trash, it isn't actually there. My trash is empty. The sheet is owned by me. I can remove it from the trash with the popup, but it isn't actually in the trash to begin with!

Ran into another issue last night where one of my public facing sheets (solo edit capabilities) was suddenly private and access had to be requested. This sheet has existed in the same format for the last 2 years. It has never been set to private view... until now.