Help! Second monitor going ON and OFF macOS Catalina

[jsaied]

Hi, I have a Radeon RX 480 8GB with two 4K monitors connected and every time the computer wakes up the second monitor starts going on and off and the only way to solve this is by disconnecting the HDMI from the second monitor, wait for the computer to move everything to the first one, and connect it back again, and this will work until the computer is either shut down or put to sleep.

The weird thing is that when I boot with Windows, I don't run with the same problem, so I'm guessing it has something to do with the software part on macOS. I'm running macOS Catalina 10.15.4. Please if someone can help because this is very frustrating to have to disconnect every time I wake up my Hackintosh. Thanks!!!

 

[Namok88]

Are they identical monitors? Compare their settings and switch HDMI port and cable to see if the issue moves to the other one.

Catalina 10.15.4 does the same to my dual 4K DP displays. To fix it I had to disable Free Sync on the 2nd monitor.

I don't have that problem with Mojave with the exact same EFI folder (OC or CLOVER)

 

[jsaied]

Thanks, @Namok88!

It was fixed by changing the monitor from Monitor 1 to Monitor 2. For the record, the Monitors are different. One is Samsung U28E590D and the Other Acer KG281K. The Samsung once connected from HDMI to the DisplayPort of the RX 580, and the Acer was connected on a regular HDMI to HDMI. When changing them, the problem was gone.