2nd Monitor causes check boarding

I have successfully got Ventura installed on my Gigabyte Aurorus Gaming 7 Z370 using integrated graphics and Coffee lake I7.

When I have 1 monitor plugged in it’s fine but when I have a 2nd monitor plugged it I get this checkaboarding effect. Is there any troubleshooting I should be looking at that might cause this?

Both 1080p monitors using HDMI and display port straight off the motherboard (no dedicated GPU installed)