erosoco: my conclusions are the same as you. It must be a streaming problem. Please keep digging!
https://forum.team-mediaportal.com/...s-stuttering-video-live-tv-recorder-tv-39384/
Known issue (winsock 1 should be replaced with winsock 2). Currently no plans for fixing (i.e. no developer around who has enough knowledge & free time on that area)