I've seen this in other vehicles
When I purchased my JKU new in 2008, it was the basic X model with no cruise or power windows, which was just what I was looking for as I planned to mod it extensively. I had the Mopar accessories cruise control, which looks to be the same as the factory version, installed by the dealer and am quite pleased.
For some time now, it is my understanding that factory engineered cruise control systems actively monitor vehicle dynamics when cruise is activated and will disengage the system if certain parameters are exceeded. The can include sharp turns at speed and steep inclines or declines. In the old days, this was done with a simple sensor like a pendulum; do something to move it too far off center and it starts shutting things down. On one of my current vehicles (not the JK), cruise control will not engage over 85MPH.
I suspect, one of the sensors is out of adjustment, but I wouldn't know how to go about diagnosing, adjusting or fixing it given the degree to which modern vehicle electronics seemed to be closed systems these days. This may be something best addressed by the dealer and hopefully, under warranty.
Good luck,
-meljr