I had the same problem with my 2011 JGC with the 430n. I fixed after doing 2 software updates. My stereo software was running version 20.02.01. I found a lionk that let me update the software to 23.04.41. Read the thread:
Burned the iso to CD (not DVD) and popped it into the stereo. Happy that doing this brought the stereo up to current firmware, it unlocked Sirius basic radio service for free (heard it might work for free for a year!), and Travel Link features as well. Be warned that I cant guarantee that running this update will do all the awesome things it did for me, but it seems that reading through several forums, nobody seems to be experiencing issues. I think the radio knows if the update is compatible and will error out before the upgrade process starts.
Once I went through the update process, I threw caution to the wind and tried the uConnect update located in the following forum post:
i followed the instructions and voila! iPhone 4s works great both connected via bluetooth (no fast music with odd pauses when streaming) and also using the USB port in the center console. For me, it is nice to have access to both ways of connecting. I use the bluetooth for phone calls/streaming Pandora/internet radio, and the USB connection lets me access all the songs using the menus on the radio.
Just because this worked for me, I can't guarantee this will fix the issue but I have a 98% feeling that it will do the trick!