Texture looks good in editor but looses every detail in viewport

Hello everyone. I have a question for a problem i never had before. After many attempts trying to fix it, i thought i would ask the pro´s what problem it could be. So, as the title already explains it, i have a material. Now, when i look at it in the material preview, it looks pretty good, but when looking at it in game, it looses every detail and light. (I know the texture is not good looking, but i was just trying sth and wanted to see what it looks, and then stepped on this problem. Maybe you guys can help me.

Thanks in advance

Is it a LOD issue? Try and force the LOD to 0.