The JSF program has been dealing with transonic roll-off since
at least 2004:
http://ntrs.nasa.gov/archive/nasa/ca...0040110952.pdf
And as of 2013, they were still dealing with a different kind of it:
"Buffet and transonic roll-off—wing drop in high-speed turns, associated with asymmetrical movements of shock waves—still affect all variants of the JSF, despite control law changes. The program will conduct flight tests this year to assess the problem, but has now reached a limit on what can be done with control laws, Gilmore reports. Further changes would degrade maneuverability or overload the structure.
More F-35 Delays Predicted | Defense content from Aviation Week
Courtney Mil wrote, "You've confused me there. Could you just explain the effect of buffet or vibration on the aerodynamics and what transonic roll off is in this sense. Please?"
My apologies. You are entirely correct. That sentence was poorly worded. Transonic buffet in the F-35 is so pronounced (at certain AoA) that it is effecting the flap schedule in the control laws. The two issues are related, but distinct, not a continuum as I implied.