Different brightness levels on the same light sources

[SuperKlever]

I’m trying to add some light to the dark areas of my scene. Now I use RectLight, which gives good and soft lighting.
Unfortunately, for reasons I don’t understand, absolutely identically configured RectLight can illuminate the scene in different ways.

Also, in a narrow corridor, RectLight does not want to illuminate the ceiling.
Are there any suggestions on how to fix this.

[ClockworkOcean]

You need a point light in the corridor

Rect light only faces in one direction.