Transparency does show textures from behind through materials in front

I’ve tried to import the League of Legends Map into Unreal Engine 5.1, after hours of trying and wrong flipped normal maps, i got the alpha opacity to work. (i’m new to this, lol)

now, where everything seems to work, i get those weird artifacts where i see textures from behind though the textures in front.

do u guys know, why this happens?

this is the texture that is being used in this mesh: