Did you Reboot after switching Drivers? If So:
Let's try setting the mode:
If connected by HDMI:
xrandr --addmode HDMI0 1920x1080_60.00
Or
xrandr --addmode HDMI1 1920x1080_60.00
If by Display Port:
xrandr --addmode DP0 1920x1080_60.00
xrandr --addmode DP1 1920x1080_60.00


