This is a bit odd. I had a first install (I guess installed via Lutris) which ran without any issues. FMVs ran well.
Now on my Deck it runs well too but FMVs do not. I should take a look into this older install, if I can see any difference.
My Deck install however is easy, just installed normally with Heroic. I can start it directly from there or add it via BoilR to Steam and do it over there.
The only thing I just can't get to working is the Direct3D11 Renderer for this engine. It's the same that can be used for Unreal, Undying, some more and Star Trek DS9 - The Fallen which doesn't want to start with this renderer neither. The worst part is, the HD Texture Pack for WoT only works with this renderer. To find it, just search for "unreal d3d11 renderer moddb".
I hope my tech support request on the linux_gaming subreddit can bring some help over this. Then I will add it here.