The line from your log:
Should indicate the SDL error but the error string is the wrong one. It should be the output of SDL_GetError() converted to utf-16.
In method
FVulkanLinuxPlatform::CreateSurface
in
UnrealEngine/Engine/Source/Runtime/VulkanRHI/Private/Linux/VulkanLinuxPlatform.cpp
try wrapping the call to
SDL_GetError()
as
*FString(SDL_GetError())
This won’t fix the problem, but it might lead you to where it is.
I’d be interested to know what the problem ends up being.