Sometimes Media Player Classic doesn't change into fullscreen mode when use right Alt + Enter combination.

Sometimes Media Player Classic doesn't change into fullscreen mode when use right Alt + Enter combination (only right Alt + Enter). This bug doesn't occur every time but frequently and has been detected on four PCs - home and office on different operating systems. The bug is not new. It also exist in the latest version 1.9.18.22 (b58777f21); Compiler: MSVC v19.29.30138; Build date: Dec 22 2021;
It's not pain in the ass of course but it would be nice if we report each bug detected.

Use F11 for toggling fullscreen.

If your right alt button is not working as "Alt" then your current keyboard layout is using it as "Alt Gr" which is for creating international characters (letters with accents and so on). One solution to fix that is to change your keyboard layout from "US English International" to "US English".