I have 16gb of vram and still get the blurred textures, but I also have my graphics settings on high and the Lumen lighting on. Have you lowered the settings yet? I ask since you didn't mention graphics settings, just that you tried dx11 and vulkan. Speaking of, it doesn't look like anything changes from dx12 to 11, but it's stuff in the background that boosts general performance not just the graphics, but if it really doesn't seem to change anything then set it to whatever you want. And vulkan is another way of doing what dx11 and 12 do, but is still catching up in some places.Changing dx12 to 11 changed nothing and vulkan makes the floor go black but beside that again nothing. I'm not sure its a vram issue since I got plenty (12gb) and on windows like i showed it has better long distance resolution compared to the Linux one. Maybe I'm missing out on a few things like dependencies to download. Any one else using Linux to confirm it might be only me?
I don't really know Linux, so I wouldn't know if Unreal Engine has dependencies on there. However, I've never heard of needing any for UE games that aren't already packaged with the game or gives a popup saying exactly what you need.