Sorry if this is not the right place for the issue. I got forwarded here by support...

Logging into a Windows PC Steam client deletes all compatibility configurations from all installed games. Logging back to a Linux PC Steam client does not return the configurations, and none of the already installed games run without the Proton configuration. This seems to happen to games that are already installed on the Windows PC and Linux PC before logging into Steam.

Is there a way to prevent the Proton -configurations from disappearing?

Proton version: all
Games: all Windows-only games that require Proton to run, and have been installed on Windows PC before login