Illumination lumen shines through objects, it is necessary to raise the camera the shine disappears, there are also often shines in the corners of the map
I’d first visualize your lumen scene to see what issues might be there. Your lumen scene is only an approximate scene representation compared to the Gbuffer, and when mismatches occur it creates light leaking or over-occlusion. It’s fixed when you see it because screen traces take over and properly block the light.
If using software lumen, make sure all major opaque surfaces have good distance field representation, and are at least 10cm thick to avoid light-leaking.