I’ve been running on Linux with -opengl4 option to UE4Editor because Vulkan would not work for me.
Yesterday I upgraded to 4.25 and thought I’d give this a try. By co-incidence I happened to have my Engine Scalability Settings in my project down to Low.
Lo and behold Vulkan at low resolution works just fine.
I tried increasing the Engine Scalability Settings but every time the engine would crash.
So the bottom line is that the Vulkan driver on a GTX 950 with 2GB cannot handle a 4K monitor on anything other than low res.