Soldato
I had the same thing on my Dell 24" 1440p screen. Black flashes for a second or two randomly playing games or even on the desktop, I bought a new cable and it's still in the box. I haven't had it happen for months now but I'm not 100% sure what i did that sorted it. I think it's something to do with the power saving feature though as that's what I was fiddling around with last.Happened again tonight first time since I put new cable in 1st July 7 bloody days I thought it was fixed.
So I am now reading about other users fixing the same issue by increasing the override from Radeon settings voltage swing.
I am running 3m 1.4 display port cable its certified but I wonder if this length of cable is the reason?