Thank you very much for confirming behaviour.
You are right, it occurs even with vxgi turned off.
Well, for me personally it’s not that much of a problem as one could still use flat tesselation, but maybe it will get fixed soon.
I also converted a project of mine to 4.15.1/Volumetric/VXGI. I turned VXGI on and didn’t see any of the flickering stuff like in the ShooterGame.
But there are not that many particle emmiters in it yet, just some fire particle systems.