Hi - I get this sometimes (have for a few years) and I haven't had my op yet. Feels like a burning, numb, tingly sensation?
My GP told me (in the nicest possible words) that its wear the belly overhangs and nerves don't get a straight direct line down from the torso to the legs (they go on the scenic route and get bent going down to the bottom of the hanging belly then back up and then down the leg) so you can get numbness in your legs!
I know it sounds strange, but when it has happened I've lifted the belly a bit and it's eased it, like unblocking a kink in a garden hose!
I know you're post op, it could be as your losing weight the change in body size could mean the nerves are free to move more and this may mean that they're getting caught up.
Believe me I'm no medical expert so still get it checked out but that's what I was told - funny as it sounds, or he may have been humouring me lol!!
Hope you get it sorted hun.