Hi ! Did you check your backups folder if there’s no broken/temp backup that takes space? It happened to me several times.
To check where the disk space goes, I use the command line tool ncdu. This is how I figured out my issues.
Note: If you ran out of disk space, don’t forget to verify that the remote download images setting hasn’t been automatically disabled because of this. We are supposed to get notification about that, but I somehow missed it multiple times. I’m not even sure I got this notification.