OpenGL might not work because of some X11/Wayland bug, outdated drivers or security reasons, like AppArmor: https://gitea.wildfiregames.com/0ad/0ad/issues/7582.
To help us you try to run any other game under OpenGL (like supertuxkart).
That's interesting. Probably we're doing something differently. I can try to build a modified version of the A27 pyrogenesis.exe with some fixes and send it to you if you can run and test it.
Is it windowed or fullscreen mode? Could you attach your logs? You can find a path to them here: https://gitea.wildfiregames.com/0ad/0ad/wiki/GameDataPaths
That's interesting. I'd say that's a problem on the driver side since it's related only to the VGA case.
Do you have any other game that supports Vulkan? For example, SuperTuxKart.
Nothing suspicious in the logs. Does the GPU skinning work with OpenGL?