HDMI out stops working few seconds after app launch

Hello,

I tried HDMI out to display with my brand-new GPD XD 32GB. It seems working but video/audio stop working few seconds after any app launches even if it's settings. Display gets black out and no audio. If I put the device sleep and resume, video works on lock screen. However, if I switches to any app, the problem occurs again.

Does GPD XD's HDMI out support apps? I want to watch youtube/amazon video, or games on big screen. It it possible?

It works fine after switched to another HDMI adapter. Sorry to bother.