If you are using emmives to light the scene, then that’s what causing the noise.
The smaller and brighter an emissive is, the more noise it brings.
Keep emissives big and dim and add regular point lights instead.
Make sure you are using TSR or TAA with these commands as a temporal solution is needed to find EDIT hide Lumen artifacts.
For TAA here are my commands for it(use default for 4k, maybe bump up frame weight)