Hello, I am also running Sapphire RX560 (4GB) with 3 screens; and I also like to switch between Eyefinity ON/OFF depending upon what I’m doing.
The first time I switched Eyefinity off I also lost two screens; however, all you need to do under Windows, is to enable them in the Display Setting.
1. Right Click mouse anywhere on Windows Desktop
2. Click on Display Settings
3. Click on Detect – this should show that your other two screens are present
4. Select them on by one, and in the box under (Multiple Display) choice “Extend these displays.
Now I can just switch Eyefinity ON/OFF whenever and thes display will always revert back to whatever state they where in before the use of Eyefinity.