PMP stutters on TV, not on monitor

I built a new media PC for the living room.
I set up the PC while connected to my other monitor (1080p 60Hz), installed Windows 10, drivers, etc…
I installed Plex Server and the Plex Media Player, loaded the HDD with movies, set up the library. I played few movies (while connected to the monitor), worked flawlessly.
I take the PC and connect it via HDMI to the TV in the living room… suddenly all movies stutter. VLC works great without any stutter.
I played around with the settings and I managed to make it a bit better by enabling Display Mode Switching and setting Sync mode to Video but the judder/stutter is still quite aparent. HW Acceleration is turned ON as well.

I took the PC and connected it back to my monitor… works fine. IDK anymore…
Even streaming with Transcoding or at Original quality works just fine from that PC. If I play movie on the TV from USB it also works just fine.

Ryzen 3 1200
GT 1030 (HDMI)
2x4GB RAM

IDK anymore. Thanks for suggestions.
(Doesent matter if I play x264 or HEVC videos, all stutter/judder).