The lighting is flickering in a VR template project after turning off forward shading for seeing Niagara effect

Hi everyone! I am working on a VR project which needs to use Niagara smoke.

I saw another problem about “Niagara doesn’t work in VR template” - (How to make Niagara Fluids work in VR template? UE5.3.2). It said turning off Forward Shading can make it work, and it is true. But then the lighting of my scene looks like the following video:

I tried to turn on/off instance stereo, adjust anti-aliasing, or adjust some setting in the Lumen GI in post process. Neither of them work. PLEASE, help me! Thank you very much!

BTW, another thing confused me is the Niagara fluid in VR project don’t have interaction with light. Like the following screenshot. One is in VR template, another is Third-person:


Yes, and this is weird that the lighting doesn’t have problem in my new opening VR project. Please help me!!! Thank you!!!