Hello Ilya, TL;DR: It turned out to be an issue on my end I guess.
Before reporting, I tried many troubleshooting steps: uninstalling and reinstalling, downgrading to 0.7.2-2, upgrading again to 0.8.1-2, resetting the config, even reinstalling the nvidia drivers, rebooting at every step. The result was always the same: 0.7.2-2 worked, but 0.8.1-2 did not. After your reply, I decided to uninstall mangohud and test the pre-packaged 0.8.1 release from GitHub, which worked correctly. Next, I removed that and built 0.8.1 from source, again, it worked. Finally, I uninstalled my source build, reinstalled the Debian 0.8.1-2 package, and, unexpectedly, it started working as well. At this point I'm not sure what exactly was wrong, but everything is working now. Thank you for taking the time to look into this and best regards!
