Directional light doesn't cover all my skysphere, looks really strange

Hi, I am new at UE4. I have assembled location and decided to start set lighting but when I added the direcational light I noticed that it covers only part of my skysphere (see screenshot). Is it possible to fix or what am I doing wrong?
I am reading docs now but there is nothing about it there.
A little help please.

Your skysphere should get all its color from the emissive channel, not the diffuse. Lights shouldn’t have any effect on it.

Your sky should be set to Unlit and use the emissive channel.

Thank you kindly!