If you join someone that sends you and invite who then gets placed in a game. You basically end up in a screen with the other players showing muted and he has no idea you are there waiting. The only way you can tell if he is in a game is clicking on the social tab and looking at his name inside the squad. I think in the main screen there should be clear UI showing that the player you just joined through his invite is actually in a game now and doesn't know you joined him.
#squad UI
molten violet
novel escarp
This is mostly because of inviting players crossplay being off.. it ONLY works for squading up not random teammates or opponents
tall orchid
there is ALOT o fbugs with the scoial UI on xbox lately
ill play wiht someone and after they get offline off the grid will say that that person who got offline is "IN LOBBY" for like HOURS on end
it will show someone online who hasn't been online in nearly a full day
let me summarize