I can give some suggestions since I am not part of Laminar. Someone from Laminar will eventually respond to you
This is the most bizarre thing I've seen yet
1) Update your graphics driver if needed
2) Is any of your computer parts going bad such as your monitor? (pixels). Does this flickering happen with any other games or while browsing the web?
3) Is this the "stock" sim
4) Delete your preferences files inside the folder to reset the sim