I am also having this same problem. Anyone figure it out?
This happens when I have multiple static or movable rect lights with large or overlapping attenuation radiuses. I understand stationary lights should not overlap more than 9 times (I think), and I have 30 of these. Is the issue related to that somehow?
If I set my lights to static, the problem goes away… Which is fine if you want static lights, but they produce terrible shadows compared to static or mobile lights with ray traced shadows and they do no illuminate the scene as well (could be user error on my part).
Thanks in advance if anyone can help here.