Puckstop

Just dropped off my 2015 Yukon for a vibration in the rear. Noticed it the day I drove off the lot. It wasnt entirely consistent but started at 70mph thru about 80mph. I figured it was just a tire balance issue until my service advisor called me today and told me it was a known problem and they would do what they can. I have 2 other issues with it as well; the bottom 3rd of the radio/gps display will flicker from time to time and when I plug a phone into the usb ports, I get a frequency feedback thru the radio. Tried multiple cords and phones with same result. Anyone else have similar issues?