This is, and has always been, one of my biggest complaints about the game. The integration to Steam is lacking. There’s another thread that complains about the use of tab as a hotkey on the menu screen, which interferes with accessing the Steam overlay by pulling up the “role preference” screen. But this… being unable to add players you just played with… that’s a pretty big buzzkill, and makes the community feel really small sometimes when you can’t find the people you just played with. It also doesn’t seem like “Player Options” is always available throughout the game, only during loading before the round begins? Which compounds the problem.
I think this is definitely an area TRS should devote some time to fixing. This has been a problem for way too long. The only time I ever remember it actually working was the beta, if my memory serves me right.