Linux Newbie here to say great work for this type of program. I thought by moving to Linux, I've lost compatibility to my many games. Thankfully there was a path already made here.
Anyway there techily four games I'm having issues. The fifth game launches except I'm getting low fps and my GPU usage is sitting at 40%. The names are Resident Evil 4 2023, Hi-Fi Rush, Persona 5 Royal, Haste and Viscera Cleanup Detail. Just for reference I'm using the flatpak version and already ran the reinstallation and update to heroic launcher and mangohud.