To solve the terrain bug, you can replace the patched wine file with its old version. You can copy this file https://bugs.winehq.org/attachment.cgi?id=69209 from here (https://bugs.winehq.org/show_bug.cgi?id=41930) to your Proton installation. First save your old file to a save place (for example, cd ~/.steam/steam/steamapps/common/Proton 5.0/dist/lib/wine && mv gdi32.dll.so gdi32.dll.so_orig). Then you can move the downloaded file to the folder cp ~/gdi32.dll.so ~/.steam/steam/steamapps/common/Proton 5.0/dist/lib/wine cp gdi32.dll.so