Static light become darker after building

Hi!
I need help in solving the problem that I faced.
Static light placed in a level become darker after building
Light becomes darker or disappears altogether.
If I use a stationary light source there is no problem. But in order to save computing resources I need to use a static light. I added screenshots of viewport, material parameters, UV and metallic texture.
Thanks in advance.

Windows 10 x64
UE4.14

How did you fix it? I have the same problem.

To be honest, I do not remember how I solved this problem. As far as I remember there was a problem with the settings of compression parameters for reflection maps. Now this problem is no longer exists. If there is a possibility, can you give me a test level of your project so I could try to figure out the source of the problem.

I’m having the exact same problem.