Can you provide logs from Saved/Logs in you project directory. Also you could install debug symbols (in UE4 installation options) which would allows to see more from stack trace.
But form what you show i can see one thing, the crash happens in the driver while UE4 talk to DX12, so this dont need to be UE4 bug, but also DX12 (DXR) or driver bug. More hints might give stuff i mentioned above, so if this is a bug we might figure atleast what you should avoid