Try this clip for example, it's 4K HDR encoded in H.265 / HEVC, I don't know if that makes a difference:
http://www.mediafire.com/file/m83ftn7n8d8le2s/Plane_Crash_Scene.mp4/file
Stutters in the default video player app for me. One thing to note is that it's smooth in portrait mode, but the moment you rotate into landscape fullscreen, it starts dropping frames. Now, turn on the screen recorder from within game tools and the stutters are mostly eliminated. What gives?
Another way to compare would be with a video player that lets you switch between hardware and software decoding, like MX Player. Watch the clip in HW mode and then switch to SW - it's choppier in HW mode for whatever reason. Using SW is not an option as the colours are not displayed properly and battery drain is much higher.
Regarding the clip - if it's against the rules to post such content, let me know and I'll remove it. There's a whole YouTube channel full of this stuff, I don't want to link to those as the problem I'm encountering is related to local video playback.