Roz,
Could it be something else, related to medication. 9 Months is too long to be anesthsia, but, it could be something else medical or medication brewing.
Have some blood work done, there may be a small chance of some scar tisue growing around the vascular bundle too, maybe a MRI or something could show that.

Check your sugar, thyroid, even heart for some kind of issue.
BY playing deduction and ruling out, medical or medication then can start to say maybe some scar matter or adhisions where they don't belong or other issue.
Is it any other times, like waking up, or sleeping

I would cut down on length of walk, and make sure you support your ams on a fanny pack or pockets, don;t swing them. Swinging arms is a big no no to TOS whether post op or not.
Hope it resolves,

di