Problems with video playback on Windows with HDR enabled

[Jaime]

Apologies if this isn't the right forum.  I've been having performance issues when playing 60fps videos on Chromium-based browsers when HDR is enabled on Windows.  It happens on Youtube, Twitch and even downloaded 4K videos from Youtube played locally on the browser.  I consistently see dropped frames when the video is on full screen or even if I just increase the size of the browser window and video.  I've been trying to find a solution the past couple of days but none worked.  A lot of the solutions don't involve HDR.

I've tried Google Chrome stable, dev and canary, the latest Chromium builds and Edge Chromium.  Happens on all of them.  I've seen it happen on the latest release version of Windows 10, the beta channel and now the dev channel.  I'm using a laptop with an Intel 9750H, UHD 630, Nvidia 1660Ti, 16GB RAM and a 4K 60Hz OLED screen, no external monitor.

I'm not entirely sure the problem is solely on Chromium.  But here's what I've been seeing:

• No issues with HDR off.  Even 8K 60fps videos on Youtube play smoothly on full screen.
• With HDR on, 60fps HDR or SDR videos of any resolution start stuttering and consistently show dropped frames, even at 144p.  While 30fps videos are fine even at 4K.
• Downloaded videos from Youtube play smoothly using PotPlayer.
• With HDR off and playing a 4K video, Task Manager shows the browser consuming about 40-50% iGPU and Desktop Window Manager about 2%.
• With HDR on, the browser consumes the same, but DWM spikes to 35-45%.
• But I see the same numbers with PotPlayer and the video plays smoothly.
• No issues if the browser window is just taking up about 1/4 the width of the screen.  The stuttering starts if I resize the window to more than 2/3 of the screen.
• Forcing the browser to use discrete graphics doesn't help.

Anything else I can try?  Any help will be much appreciated.