Same today on a server case3 mission with 5 pilots online:
only difference: I use Vaicom, the rest not, but Vaicom is not queueing commands, I did all inbound calls via keyboard.
The only other difference: when I had to leave the server to re-install SRS I reconnected.
I suspect my client registers with the SC but does not un-register it when the role changes / client leaves.
I got calls for 411 all the time while I *was* 411 but it was 416 actually talking to ATC.
Everybody else was fine, but everybody else stayed in their slot right away, hence my suspicion.