KSP 1.8.1 minimizes when clicking icons/buttons

[Yamiko Hikari]

I have a 1.8.1 KSP modded install. I've been playing it for over a week and it's been fine. Today I launched the same save file and the icons for different mods and stats are working weirdly. When clicking the icons/buttons, that are in the right bottom corner of the screen when you're on the KSC screen, the whole game just minimizes. It happens both with mod icons, such as TAC LS, Remotetech, Alarm Clock and others (happens to all of them), and non-mod icons such as active contracts, messages and informational icons in the tracking station screen that show the information about a planet for example. The game is in 1920x1080 fullscreen and switching to windowed mode fixes the issue, but obviously I'd really like to keep playing in fullscreen, so I'd really appreciate your help.

I already tried verifying integrity of game files through steam. It says around 43 files are corrupted and restores them but the issue still remains after this and running the verification again and gives the same "43 files are corrupted" message.