Disable media mediacodec (surface) this will help with video stutter.
It is in video settings - acceleration, it's enabled as default.
I did have this issue with Jarvis too: IPTV steams freezing, stuttering, buffering a lot. Disabling both acceleration fixed it instantly...
Edit: still a very inconvenient way for everyday use, as one should always re-enable the accelerations for, like DVD playback every time... (As we know the DVD deinterlace issue still hadn't been solved in Hiplayer, so the usage of KODI instead is essential in these cases...)