Thank you @mitu. I would never have guessed that setting controlled it. Works like a charm.

Thanks @mitu @Efriim Apologies not to answer before. Turned off OMX and everything same with arcade game videos (some of them). Tried to convert with handbrake w/o any scrift (very easy to do...and tried some different configurations) but no luck. The only option was to download .mp4 from YouTube...and works and I dont know why. Its rare because the video was the same from the beginning I was made couple months ago and did work perfect, so its not a Skraper/XML problem...I think EmulationStaion is on the last build 2.8.3RP Anyway, many very thanks.