Re: Fourth player doesn't show up on player list in-game, end-game summary

That's really strange I never had that at all. If they were good team mates otherwise I'd just write it off as a glitch.

Generally speaking you can always send us a report on players when you have the feeling that there is something wonky going on. Please read here how to do that best:

https://help.ea.com/article/how-to-report-cheating