I might be having a similar issue trying to play a 4k SDR HEVC video on a Celeron J5005 with video acceleration enabled.
The audio plays, but the video does not appear, and instead the menu interface starts flickering.
Video info
Video
Title: 4K HEVC SDR
Codec: HEVC
AVC: No
Profile: Main 10
Level: 153
Resolution: 3840x2160
Aspect ratio: 16:9
Anamorphic: No
Interlaced: No
Framerate: 23.976025
Bitrate: 15150 kbps
Bit depth: 10 bit
Video range: SDR
Video range type: SDR
Pixel format: yuv420p10le
Ref frames: 1
The video is being played through Jellyfin's Jellycon, so technically streamed, though the Jellyfin server itself is hosted inside a docker container on the same machine and accessed via a localhost ip.
I will post a LE log as soon as I am back home.