Screen partially black only mouse pointer visible at startup

[Windows Central Question]

Hello, I have a strange problem sometimes when I startup Windows 10. Basically when I reach the login screen sometimes only the top left quarter of the screen is visible while the rest is black and I can only see the mouse pointer. The PC is working and I can login and do other operations also in the part where the screen is black.
If I press Windows+P or Windows+CTRL+Shift+B the problem disappear and I can see the full screen, but eventually if I turn on another time the PC the problem can occur again