Ive noticed recently after getting my new monitor that I was experiencing some flickering while using my Affinity programs. I researched some NVIDIA forums where they suggest changing the NVIDIA setting for g sync from enable for windowed and full screen mode to enable for full screen this does correct the flickering issues however that also affects other things you use G-SYNC for if you game as well as edit in graphics programs then this could be something you do not wish to change.
So for those whom have G-SYNC enabled and are running NVIDIA cards a better solution is to change the G-SYNC settings in the NVIDIA control panel for a specific program.
Open the NVIDIA Control Panel, click on Manage 3d settings, Click on the Programs Tab, use the drop-down to select Affinity photo, or Designer , or Publisher, and scroll down to the Monitor setting for the specific program and change it from
use global setting (G-SYNC Compatible) to G-Sync Compatible, click apply and restart your program this should remove the flicker issue both these solutions worked for me hope this helps anyone experiencing the flicker issue.
If your program is not listed in the programs list click the add button and browse and add it to the panel then change the setting.