This started out of nowhere. My laptop has Nvidia mx150 and intel 620U graphics. When in Nvidia control panel Global settings "auto-select" is selected. Every game that is native fullscreen has a black screen while the sound works and the game can be interacted. I can't make them windowed because they aren't from steam. Games kinda work when preffered card is set to Nvidia. The problem seems to be with the intel one, but not sure what. My nvidia drivers are clean reinstalled and updated. Intel drivers are updated. Windows 10 updates too.
Try going into your bios and disable the intel card it seems that when u play a game that is not graphics intense the intel card takes over but is how they work their nothing wrong with your system in my opinion does two in one video cards are not the best for gaming.
Another suggestion is to safe bios settings as a profile (so you can revert back to it if need be) and then BIOS load defaults. Load your game and see how you go.
Op has disappeared after making his first post. I'm too having this issue with my HP notebook. Insyde Bios update changelog mentions this issue and I have updated my Bios but the problem persists.