Valve has released the Version 4.2.8 of Proton in the Steam Client for Linux:

4.2-8: Fixes for games which embed web browsers using the Steam client. For example, Football Manager 2019. Fix an issue with Bloodstained: Ritual of the Night and other titles crashing with an error dialog on exit. Upgrade wine-mono to 4.9.0, which includes winforms support. This may help some game launchers. Various window management and alt-tab fixes. Fix for controllers losing force feedback when removed and re-added.