Thanks for the tip
my R one always slipped off of the plastic (thing-y??) whatever that is called, but now I have a new afo for rightie, so I'm no longer using it.
The new brace was causing me lots of problems chafing at first. I tried wrapping my leg in just about every soft wrap to no avail, tried wearing two pair of cashmere socks; no good.
On a whim I tried 3" wide sports tape wrap, the type that sticks to itself. (I'd originally bought it to use to cover up the blue strap over my instep which shows when wearing jeans, make it less noticeable when going without socks) and did it ever do the trick! The texture of it gripped my leg, and was thick enough to shield it from rubbing.
Oh, about the strap popping off, that can really hurt, this summer I thought something BIG stung me, and it was just the snap of the strap coming off.