Unless you are talking about near black VRR flicker, which is common on all OLED panels, there should not be flickering and if there is you should RMA it, so in other words you'll find people saying no their Asus monitor doesn't flicker with Gsync because it should not unless something is wrong with it
This type of flickering is common on all OLEDS:
The only way to stop it is to use vsync in games that flicker. Or you can somewhat mitigate it by raising your monitors gamma level and the games brightness