Bug VideoPlayer videos do not play on SteamDeck

When I run a Windows build made with Unity on SteamDeck, the VideoPlayer does not play the video properly.
A color bar like the link below appears instead.
https://www.reddit.com/r/SteamDeck/comments/wnn1ok/colored_bars_during_game_movie/

I have checked with Unity2020.3.18f1 and Unity2021.3.16f1.
Does anyone have any information on this issue?

I tried H264 and H265 codecs, but neither worked.

I read on the forum that it can be cured by adding Proton GE.
As a game developer, I want it to work with regular Proton.

 

I got it to work by setting the Codec to VP8...

 

There is a format compatibility table and recommendations in the documentation for Unity video player https://docs.unity3d.com/Manual/VideoSources-FileCompatibility.html

 

Thank you!!