story time:
I use onedrive for sharing some files and shit. So one day one of my folders, which I got from a downloaded zip, caused an error "files couldn't be synced because of unallowed character in the title".
Turns out there was a space at the end of the folder title. I change the name, I get some error.
"Okay, no problem, I don't need that folder anymore anyway" So I delete it, doesn't work, the error message reads "Can't delete folder because it no longer exists.". "What the hell" try deleting it some more. Emptying it before deleting. Deleting the parent folder. I try formatting it before deleting. Nothing works.
Deleting from the online onedrive client causes it to briefly disappears but refreshing places it back right where it came from.

So I resort to my last hope, customer support.
I explain the whole thing.

I get a reply. Oh boy.

I get explained that if the recycle bin is full, the file will be placed back.
After that, I get an explanation on how to remove a file xD

Thanks OneDrive Team, really helpful.