This has been linked to a warning setting you have with the Nav. I thought there was a school zone or similar one, but I can’t see it in my screens shots of the current (14.05.3) and last version (13.51.1) of Uconnect.
What version of Uconnect are you on?
Re Cruise Control, it should turn on below 40km/h but of course not set (Resume from 20km/h). There is a service bulletin for cruise control to fix another issue, but it may help with your problem too.
See the details here -
http://www.wk2jeeps.com/tsb/tsb_wk2_1801914.pdf
Is this the problem you are getting? (video shot while stationary, but replicates what happens while driving)
https://www.youtube.com/watch?v=MrZ2fmPuTXA