Amazing, this extension really seems to be doing the trick. At least playing fullscreen videos in Firefox and Gnome Videos seems to be working again. But Kodi still doesn't work corrently. There is a huge dark border around the actual Kodi window, as you can see in the picture that I attached.
The Ubuntu wallpaper bottom right is my from my second Full HD monitor, if you are wondering. ** Attachment added: "Bildschirmfoto von 2020-10-04 18-14-25.png" https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1890141/+attachment/5417551/+files/Bildschirmfoto%20von%202020-10-04%2018-14-25.png -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1890141 Title: Can't fullscreen, or windows get automatically un-fullscreened, when using fractional scaling Status in mutter package in Ubuntu: Confirmed Bug description: Same issue as this one: https://bugs.launchpad.net/ubuntu/+source /gnome-shell/+bug/1863391 Some websites like YouTube will attempt to fullscreen, just not successfully. Other websites, like Netflix, will fullscreen for a second and de-fullscreen after that. Some games act weirdly in fullscreen mode (this might be related, as I've never had this issue before now: https://github.com/ValveSoftware/csgo-osx- linux/issues/2429). EDIT: This only happens when fractional scaling is enabled. My config; main 4K screen at 150% and secondary 1080p screen to the right at 100%. YouTube fullscreens fine on the sec. screen (1080 100%). This is a gif I posted in the related bug report showing exactly what happens: https://bugs.launchpad.net/ubuntu/+source/gnome- shell/+bug/1863391/+attachment/5397743/+files/20200731_160007.gif ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: mutter 3.36.3-0ubuntu0.20.04.1 ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44 Uname: Linux 5.4.0-42-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.4 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Mon Aug 3 14:03:00 2020 InstallationDate: Installed on 2020-07-30 (4 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) SourcePackage: mutter UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1890141/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp