INFORMATION REQUIRED WHEN POSTING A QUESTION Provide your full system info!
DVI+DVI+HDMI+DP? Any adapters?
1.Leave only one monitor for this operation:
2.Uninstall any software for GPU and system tweaking
3.Delete C:\AMD folder
5.Then reboot and plug your remained monitors one by one,checking at each step, that Windows has installed correct driver for each monitor