Hello guys!
So issue is, that when I work with Krita, and uses shortcuts (I think mostly ctrl+left click <- stylus) Krita is doing strange things... screen starts to flicker and after that I cannot draw on canvas... even with mouse! What helps is restarting Krita and disconnecting tablet. Steps I took to try solve this issue:
*Upgrading Krita to newest version (4.2.5)
*Upgrading Drivers for tablet to newest version
*Switch between wintab and windows ink (I have windows 7)
*Reinstalling both Krita and tablet drivers after windows updates

Nothing helps, tho after reinstalling there was over an hour of good work without issues, after rebooting system, issue is back...