sunbuminaz

I have a 2013 Suburban 1500 LT. Upon starting the vehicle the radio looks on and the dials work but no sound comes out. Then after 1-2 minutes the radio display will flash Audio Muted and a loud static sound comes on real quick and then the sound will work and then the display shows the channel its on. I have had it at the dealer 4 times now. The first time they replaced the radio. The second time they replaced the amplifier. Third time replaced the mute button on the steering wheel. It's been there now for 2 weeks and they said they have no other ideas what it could be. They are having GM assist but so far nothing. Anyone experience this or know what else it could be?

Thanks,
sunbuminaz