As soon as the Keyboard Shortcuts tab window is invoked in the Settings Application, Right Alt key is switched off system-wide. This happens suddenly even without any action from the user - just simple invoking of the window is enough to break the settings.
This obviously happens because of the new setting in the Keyboard Shortcuts appeared in focal: Alternate Characters Key. It sets Right Alt by default immediately as this window is opened. This setting doesn't have the Not Set option, so it is even not easy to switch back to the normal behavior. This setting can be unset only through the GNOME Tweaks application: Keyboard & Mouse - Additional Layout Options - Key to choose the 3rd level - uncheck the box Right Alt. But this is not a good workaround since the Alt key setting will be destroyed again as soon as Keyboard Shortcuts are visited in Settings next time.
The reasonable workaround seems to be introduction an option Not Set in the setting Alternate Characters Key and making it default. This will fix this bug and will introduce a sane default value because not every keyboard layout has a third-option for the keys.
This is quite significant UX flaw since nothing should be changed without explicit user action.
ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gnome-control-center 1:3.36.0-0ubuntu2
ProcVersionSignature: Ubuntu 5.4.0-14.17-generic 5.4.18
Uname: Linux 5.4.0-14-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu20
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Mar 15 22:33:08 2020
ExecutablePath: /usr/bin/gnome-control-center
InstallationDate: Installed on 2019-04-25 (325 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan EANIMAL" - Alpha amd64 (20190425)
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)
Thanks for your report! I could easily reproduce this design flaw, which really should be fixed before the release of Ubuntu 20.04 IMO.
It's an upstream thing, so it would be great if you could also file an upstream issue:
https:/
If you do, please post a comment here with the URL to the upstream issue.