Hello @kallestrop, this reads like game engine specific behavior and 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/5049#issuecomment-1032592697.
When creating a symbolic link for a game config file located in
/home/user/.local/share/Steam/steamapps/compatdata/227300/pfx/drive_c/users/steamuser/Documents/Euro Truck Simulator 2/profiles/56616E696C6C61, the link will always be overwritten after changes are applied in game config menu.How to reproduce:
~/.local/share/Steam/steamapps/compatdata/227300/pfx/drive_c/users/steamuser/Documents/Euro Truck Simulator 2/profiles/56616E696C6C61controls.siitocontrols.referenceln -s controls.reference controls.siiNow start the game and apply changes to a keybinding. After that, symlink is overwritten: