Yes, unilateral symptoms can be related to spinal nerve roots, especially if the pathology affecting the nerve root is asymmetric or not bilateral.

It takes time for nerves to heal and there is also the possibility it's too damaged to recover. What did your post op notes say? Did they see compression?

Also, make sure they haven't overlooked any cysts in the area. Surgeons are classically trained to ignore them but they can be problematic too.