I was dealing with this issue for months, switching cables, drivers was even about to sell my acer 4k curved monitor. Partly the driver has to do with this and they drivers are getting better for AMD/Nvidia , but i think the solution is hiding in your Monitors OSD menu the entire time. After trying all the methods from internet switching my mode from DP1.2 to DP 1.1 in the monitor setting fully solved it for me. Its been a week since i switched it and not 1 black screen, i don't even get screen flickering anymore. Great thing is switching this does not affect any graphics or refresh issue, im still at a solid 75hz on my 4k monitor using crimson 15.2.1 driver and using a DP 1.2 cable (that came with monitor). So try doing this and let me know if you have success. Im positive it will work as i was on the same boat as alot of you here but this one DID IT. Good luck and keep me posted.