This issue has been driving me crazy in the past two weeks or so and I wanted to see if anyone else is running into it. Ever since upgrading to High Sierra (I think), if I leave my MBP asleep for a few hours and come back to it, I can't play any demanding games without getting extremely low performance. I think what is happening is that the Radeon Pro 560 GPU refuses to turn on, because if I use gfxcardstatus to force integrated only the performance doesn't change. When the computer is in this state, it *thinks* it is using the dgpu (according to the Activity Monitor), but it sure doesn't seem like it. It could also be that the dgpu is stuck in a low power mode, but I don't know for sure. I've reformatted and reinstalled macOS from scratch, tried running diagnostics, reset PRAM+SMC, etc. Rebooting the computer *does* fix problem, but I shouldn't have to do that for this thing to work. Is anyone else seeing this issue, or do I have some sort of hardware issue?