Hello, that is a known issue, there is a new memory management in place that is causing these from time to time. The current workaround is to disable this.
What I did is add it to my project DefaultEngine.ini
[SystemSettings]
r.Vulkan.EnableDefrag=0
or just disable this at runtime by the same cvar (r.Vulkan.EnableDefrag). It is the best that can be done for now. They are still working on it, 4.26.1 and 4.26.2 are slightly better but still crash from time to time (with the Defrag enabled).