On the 23rd February 2022, all BattlEye protected servers kick client running on Linux with Proton compatibility tool. BattlEye: Bad Packet is send to the client within the minute following the initial connection.
https://github.com/ValveSoftware/Proton/issues/2364
This issue should be considered a regression as BattlEye is supported on Arma 3 from the 8th November 2021.
https://feedback.bistudio.com/T148823