Does anyone have issues with their graphics like this when adding mates?

After the mate is placed:

I am running SW 2018 SP5 with a Radeon Pro WX 5100 graphics card, paired with a i7-7700K CPU.

I have updated and tried to reinstall the latest drivers without any effect on this display issue. To get around this I have to select both items to mate, then click mate. The quick mate flyout toolbar doesn't show up when I have my property manager tab pulled out onto another monitor.

Thanks,

Ian