I used to be under the impression that jump stabilization gave you immunity to things like SBs...it turns out that it doesn't...
The way the files are set up, jump stabilization simply decreases the damage done and AM lost when jumping from an SB...
The engine does work...you can make it so that jump stabilization would make the effects zero, but the devs did not choose that route...
In short, it's not a bug...at most it is a very misleading string description...
If Vasari weren't so OP I'd be up for giving them true immunity to SBs, but as it stands there are far more pressing issues...