“Staircase” pattern on x265 videos…. only visible in Kodi, not in WMP

every since Krypton Alpha x265 videos when played in Kodi exibit what I would call “staircase” pattern, that comes and goes at random.

But it visible throughout 80% of video.

I know the files are find, because it does it all x265 files in Kodi, but same files are fine in WMP.

First I though that it might be doing this because I was running Alphas, betas and RCs, but yesterday Final version of Krypton was released and it still does this.