Did some more digging and it looks to be a similar issue mentioned here for a different game.
Confirmed it is related to other issue. The other issue mentioned that GE-Proton9.13 works.
I installed GE-Proton9.13 and videos play.
I also installed the latest GE-Proton9.22 but the video failed to play.
@comprofix It looks like you need h264 unlocked to play the videos on non-GE proton. You can unlock it by running this in a terminal: steam steam://unlockh264/
It sounds like there still might be a Proton-GE regression, which I'm sure they would be happy if you reported to them, assuming that unlocking h264 does not fix everything.
@alasky17 Just as a note, in a different game I was having a black screen issue. The command you provided resolved the issue.
steam steam://unlockh264/
Running Mint 22.1
Proton: 1738780315 hotfix-20250205
SteamGameId: 1210600
GPU: AMD 6900XT
proton9.13x1 2024-12proton9.22x1 2024-12proton experimentalx1 2024-12
Compatibility Report
System Information
I confirm:
Symptoms
Video's not playing but audio is. Looks like a codec error.
Full Log - https://gist.github.com/comprofix/a63fc06e2d29b0cf5ad59045b92d98d4
Reproduction
I have tried other Proton version and issue still occurs.