I was controlling ground at EGLL on TS and had my controlling time set to 1 hour, when that ran out i refreshed it. 5 minutes after i realised their was another person controlling as well, so aircraft were getting 2 different instructions from 2 different people.
Idk if its a bug or not because im sure it used to come up with “(obs)” if their was someone else controlling and you tried to join.
I didnt really know where to put this, i just wondering how it happened so i can avoid it in the future