I have a similar problem. -D3D12 and -DX12 cause my empty blank C++ project to crash after the first run. That is, it will run fine the first time, but subsequent executions of “MyProject.exe -D3D12” will throw a Fatal Exception. Attached is a zip file with my DxDiag, crash dumps, logs, config files, and any other relevant information I can think of.
I should note that MyProject-Editor.exe works fine, it’s only the client that has this issue.