I had some scaling issues on KDE Plasma after switching from a Wayland to X11 session and back again. The solution was to:
- Log out.
- Switch to a terminal (
Ctrl+Alt+F1) and log in. - Delete or move
~/.local/share/kscreen. - Switch back to a desktop (
Ctrl+Alt+F7) and log in again.
I presume this constitutes a hard reset back to defaults on the new login.
The issue seems related to these two bugs: