[macOS] Flickering when re-sizing 3d scence in DS live preview

When the project is run via Design Studio and the live preview is re-sized it flashes between a blue rect and the scene. Worryingly it seems to me that it could be close to epilepsy inducing, i'm not normally that sensitive but it gave me an instant headache and made me feel a bit queasy. (Tim checked and didn't have any problems though). I did a screen capture but i won't upload it here for that reason. So if someone else with mac wants to confirm this please be careful if you are even slightly sensitive to flashing images.