Unexplainable Lumen artifact when looking at certain angles

Hi people,

I’m encountering an unusual visual anomaly with Lumen, particularly noticeable when tilting the view upwards or downwards, or when the player character accelerates and transitions into a new indoor environment. Despite conducting numerous tests, I’ve been unable to pinpoint the exact source of the issue. What I’ve observed is that the artifact exclusively manifests when the player equips a first-person weapon and I’m utilizing Ultra Dynamic Sky as the primary light source for the map.

Here is a video of it happening in real-time:

Post-Process Volume Lumen Settings:

Thank you in advance!

That looks more like a direct lighting issue than an indirect lighting (lumen) issue. What are the shadowing settings for your directional light?

Also, if you could post screenshots of your lumen scene, that could give more insight if light leaking is a possibility.