Hmm.. any one has Apple TV + LG TV having this "screen change" symptom when watch Youtube?

My situation with all firmware updated:
1) Apple TV 4K (2021) - TVOS16
2) LG OLED CX

My Apple TV default setting is 4K SDR 60hz only with match frame rate & contents ON

Whenever i watch or exit a video in youtube, the screen will turn black for few seconds (similar to how we watch video with Dolby vision / HDR that moment) but here it doesnt change from SDR to HDR/DV.

The video stays SDR only but dunno why the "black screen"