Ok. I've solved the problem of the white window at the start on Windows 11. I've downloaded the latest release of DxWrapper (here: https://github.com/elishacloud/dxwrapper/releases), then I've replaced the old file "dxwrapper.dll" with the new one.
After this, the game started with any problem. I hope can be helpful for other players the had the same problem. Cheers!