Normals shading error

Iciban

So i'm been trying to figure this out for a while, but still stuck. Does anyone know whats the cause of these shading error? I tried cutting the edge and have it as its own separate shell, but the problem is still there. I thought it would be a bevel problem on my highpoly mesh, but the tightness is pretty tight alright. The geo is flat too. Not bending in any weird angle.  If anyone can think of anything. That would be awesome.

kodde

So both the LP and HP are flat on these areas?
If so I'd say your LPs vertex normals aren't all pointing in the same direction. This produces these gradients to counter the slightly round appearance of the LP.

Iciban

thanks, turns seperating the uv edge and adding edge loops to the lowpoly helped.