Note.
I followed up with staff and apparently the fix is server side. So the system now checks if you’ve played the stage before starting it.
So essentially you can get to the “choose team” screen again for a completed stage but then when you go to play the stage, it results in an automatic disconnect & error message.
And no, before anyone asks I don’t know if there will be a public address / explanation of discipline or whatever. Historically I believe that SGG simply did the discipline then information circulated thru the community via other means (line, discord etc…)