Gray screen crash / Game uninstalled upon reboot

[Arclath]

Hey, I hope someone can help me with this, because it has prevented me from playing Red Dead 2 for the past year. So when I boot up the game, there's a big chance (it doesn't happen 100% of the time, for some reason), that the game goes into a gray screen, and I can't alt-tab or bring up the taskmaster, and instead have to reboot the computer.

And here's where it gets weird - after rebooting the computer, the game is UNINSTALLED. Technically, all the files for the game is still in its Steam folder, but when I try to launch the game, Steam says that it is not installed.

I'm not sure if it's the issue, but I suspect it may have something to do with HDR. Here's the thing, I have a HDR compatible screen, but not a HDR compatible graphics card, but the still says it switches over to HDR when I launch a game (only had problems with RD2D though).

Any help on this insanely frustrating issue?