Dithering of Niagara Particle Effects with FSR2 in Unreal Engine 5.1.1

[Bent Vector Studios]

Hi, I'm working as an indie solo developer and recently purchased a Radeon RX 7900 XTX series card to help implement FidelityFX FSR 2 and do testing. I'm sure you're already aware of some of the problems I've encountered, and some of them probably lie with Epic's code, not your drivers. For example, having to disable ray-traced shadows or the screen renders a bunch of bright sparks.

I'm currently trying to get some good results with FSR 2.2. Overall, I can reduce the r.screenpercentage from 100 to 66 and with FSR2 on cannot see a significant difference in quality while getting nearly 2x the frame rate. However, am encountering an odd dithering effect in my Niagara Particle systems which seem to be due to the requirement to enable TSR and TAA Upsamping for FSR to work. You can see this in the image below with FSR2 enabled on the left side and disabled on the right.

Any ideas on how to fix this?