2014 gmc 2500hd possible electrical issues

[Sfarms0820]

I have a 14 Sierra with the 6.0 gas motor. A few days ago the radio stopped working still had power just no sound. All fuses good pulled battery cables to clear anything and still nothing on AM or FM stations but XM radio worked. Continued driving and then the gauges in my dash started turning off and on and message center telling me to service every system in truck( air bag,stabilitrack, etc.) and then radio screen is now black. Will do nothing. Checked grounds on dash by pillars and windshield, from motor to body and another I found from a harness to frame all look good. Truck runs and drives fine still.  Any input would be appreciated before I spend a ton at a dealership. Thanks 

[silveradosid]

check connectors on the screen and the hmi behind the glove box

[Sfarms0820]

What’s the HMI and would this affect my dash it’s acting as if I’m turning the key on and off while driving down the road