Weird linear shadow from openings

So, I’m having some weird “light propagation” in my level, and I don’t know what may be causing it. I already changed values on World Settings, with and without lightmass portal on openings, AO turned on and off and 3 different HDR’s. Different intensities and bounces didn’t solve the problem either.

Build on High quality, lightmaps at 1024, static skylight and no PP.

Updating: After chaning the skylight to Stationary, for some reason the light spread got better. Why is that?