No sound comes out of my stereo

[Conradflem]

No sound from nav, radio, Bluetooth, etc it happens randomly. A hard reset worked for a few months (by Hyundai) but I had some wiring maintenance for my transmission as the wires expanded from heat. they had to disconnect from my battery, now my stereo isn’t outputting any sound I tried a hard reset on my own and it did not work I disconnected my negative from the battery for 15 minutes and it didn’t work. I don’t play the radio past 25 out of 45 and when it does work if I get a call or use Siri the sound will cut out or if I turn on the car in the morning it could have been working the day before but it probably won’t work later on and it will start working randomly when I am driving. I drive a 2015 genesis coupe 3.8 gt and I’m lost for what to do next because I have brought it in to Hyundai multiple times before and it’s still on bumper to bumper warranty but the issue has not been resolved only been treated and I’m disappointed in the warranty system Ford uses as I bought the car from them and I’m disappointed as how Hyundai wasn’t able to figure out my transmission issues for 7 months until I had my mechanic look at it and solve the transmission issue as well as the stereo issue not being resolved either I hope when I bring in my car next to Hyundai for a keyless entry censor replacement they actually know what they are doing