Can you please look at the user story here where the invites are not suppressed once you are in another party and on a run - last nights experience of being on the final event on a lvl 39 run and an invite (from over 40 mins ago) pops up and I just happened to have my cursor in the wrong place (using flamer on hordes) so it’s a misclick before I can even react and I leave the party in the lurch. I think a few have raised this before in these forums.
You can work around this at the lower levels but at high levels and the timing is bad you can screw a run both for the player and worse for the players you are with .
It’s not even just an issue while in mission, it can happen on the Mourningstar too. Just now I tried to click on the Accept Mission popup while in a group and I got an invite from some rando in the same second and accidentally joined a different group instead of entering the mission. There is zero reason for group invites to be popping up when someone is already in a group.