Same issue, RESET WORKED!
My 8.4” Uconnect (non-nav) went blank. I thought the HVAC controls worked at first, but on follow up drive they were also not responding.
I decided to punish my back, lay in the front passenger foot area and pull the fuses out for Radio and HVAC (F128 and F130). Neither fuse was blown. I started it once without fuses then let it sit overnight. Next morning, put fuses back and it was “fixed”.