UE4 mipmap issues.

Hallo UE4 community i got some weird mipmap issues on some Meshes and I can’t figure
out why or how to change the distance for the mipmap hope you guys can help me with that.

I can’t change the distance of the mipmaps when they should change and as soon
as I open the Mesh the texture is getting high ress and don’t change at all when I back off.