I was able to fix the Untitled Note that wouldn't delete by adding content in it then deleting it. It was probably not deleting because there was already a matching Untitled Note in the trash. Maybe this is a bug?
I reboot the browser and re-logged in and it still wasn't working with the classic editor. After switching to New Editor then it would save. The old Untitled Note is still there, stuck and refuses to "Move to Trash".