Welcome to the Unreal Engine forums @hakk_hakk and happy holidays!
This topic has been moved from International to Rendering.
When posting, please review the categories to ensure your topic is posted in the most relevant space. Hopefully, this new category will help you to get an answer.
In the meantime, good luck and happy developing! 
Hey @hakk_hakk! Welcome to the Forums!
It’s a bit difficult to determine what could be the cause from the information you provided. Would you mind explaining a bit more about the specifics of your problem? For example:
- What engine version are you using?
- Are you using Lumen?
- Are you talking about the material itself or the light it produces?
Any additional specifics you provide may go a long way in solving your problem!