wincordona, you might want a second opinion on the success of your 2024 surgery.
Whenever a doctor expresses and inability to explain your pain, it's reasonable to ask for a referral to someone who would have the knowledge.
The first thing I would do because it is the fastest is to see a chiropractor. And because they give the absolute best physical exam. I would go for the exam, even if I were determined to decline an adjustment.
It sounds as though you may have spondylolithesis where one vertebra slips forward over the one below, pinching the nerves. When you stand up you are in alignment and after a few steps the vertebra slips forward. But mine is an unqualified guess.