Ah, wait, I forgot you are still redirected to the custom switcher.
- Open Settings > Keyboard, remove the shortcuts:
Move to Workspace left /
Move to Workspace right in custom shortcuts.
- Run the commands:
gsettings reset org.gnome.desktop.wm.keybindings switch-to-workspace-right and
gsettings reset org.gnome.desktop.wm.keybindings switch-to-workspace-left.
Keep in mind that you need to disable these values again, and add the original (Budgie) commands if you need or want to revert.
The Budgie commands, replacing these commands: