to me, personally, it looks wrong because it exactly follows th range direction and unwrapping simply formed a surface ranging from top to bottom. There is not much influence of the areas with actual high coherence in the displacement because they are not connected.
Maybe you can try with an image pair of different orbit (ascending or descending) to check if it produces the same pattern.
Have you considered Persistent Scatterer InSAR instead? About the STaMPS category
I think this might be more suitable.