So is the in-game chat not working when you form a group a known issue. A lot of people in my guild have this issue and go be quite honest it is very annoying because the only way to fix it is to close the app and restart it.
So basically what happens is when the group is formed and you get kicked to group chat is goes in a loop of counting down to putting you in group chat. And if you try to go into another chat it just keeps doing the same loop. Also sometimes the that's actually disappear. Fyi ps4 NA server.