Desperate. Please help

I have a 2020 Chevy Silverado 1500. About two months ago my infotainment/radio screen went black and I lost all audio (my backup camera continued to work). I replaced the HMI module and my video screen is now working but I still have NO audio (including turn signal clicks or warning chimes). I’ve checked all associated fuses and my truck does not have an amplifier to check/replace since it is a standard non-Bose system. Does anyone have any ideas/solutions for me to try/troubleshoot before getting robbed at the dealership? Thank you!