Hello @game123-support, we're tracking issues with games run with Proton in the Proton issue tracker. Also, we're using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to https://github.com/ValveSoftware/Proton/issues/3994#issuecomment-2845369007.
Okay, I understand. I provided information so that relevant people at Valve might be aware of it and they might be interested in fixing the issue.
Installing Battlefield 4 with Steam Play and joining a server results in the player getting kicked from the lobby due to PunkBuster.
Solution: Installing PunkBuster 3.8 for Battlefield 4.
It is recommended for Valve to make this change as a part of an installation script for the game with Steam Play.