Try different settings of overlay video mode under
(rightclick) > Options > Preferences > Video > Video rendering
E.g. give it a try with overlay mode 1 or 2 or RGB, wait for vertical blank, or Use VMR-9 (do you have direct X9 installed?) .....
(K-Lite comes in four versions nowadays. Hopefully you did not install everything, but made good use of the possibility to be
deselective. See
this post)