Tvheadend

Using Kodi 18 Alpha 2 Git:20180322 on W10 Pro. 64bit.
Using TVHeadend 4.3-1206 on Netgear RN204.

When playing attached stream via TVHeadend PVR plugin (via HTSP) in Kodi I get after ~15s a lot of stuttering (video + audio).
When watching LiveTV on the same channel everything is fine - problem always comes up when playing recorded file via PVR plugin.
Playing the file via Kodi and direct share access everything is fine - also playing the file via VLC (via pass) over the TVHeadend WebIF.

This behaviour occures on a some German streams with 1280x720p resolution.
I don't have this problems with 1920x1080i streams when playing the recording via PVR plugin.

I don't know if it's a PVR plugin or TVHeadend generated HTSP related failure.