@maldrichm You have been through a lot. One thing to remember is that after surgery, there is a lot of inflammation and that may last awhile, perhaps months. If this was a recent surgery, perhaps time will improve things. Another possibility is scar tissue caused by the surgical path. If you are a few months out and the vertebrae are considered fused, a physical therapist doing myofascial release may help relieve some of the tight tissue. I periodically need to stretch out my own surgical scar tissue to loosen it and stop pain and restore range of motion.

I am a cervical spine surgery patient, and I did have drop foot right after the whiplash I had from a traffic accident. It also gave me a bulging disc which I think might be L2 L3. It took a couple of months right after the accident for the drop foot to get better, and that level cracks a lot especially on rotation. Sometimes it gets stuck and has sent some pain down my leg before. I have not had surgery on my back and I have been able to manage with physical therapy stretches and mobilizing my spine. I know from imaging that my disc heights in my back are well preserved. I know that's not your situation. When I was recovering from a cervical fusion, I had pain for 6 weeks straight, and then it started getting better suddenly. It took more months of physical therapy after the fusion was set at 3 months.

I have done a lot of myofascial release therapy and it has helped me a lot. Here is our discussion about it where you may learn more.

-- Myofascial Release Therapy (MFR) for treating compression and pain
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/
This link has a search for practitioners:
-- MFR Therapists: https://mfrtherapists.com/