Have a 2017 Prius Prime Premium. Had been playing music from thumb drive in usb port. Just tried playing music from my iphone6 via Bluetooth. It will connect, play for about two seconds then disconnect. Same thing happens if phone is connected via usb port. Had three calls with Toyota Customer Experience who first said I should get a software upgrade, then said there is no upgrade available and I should go to dealer. I have successfully used Google Maps from my iphone via Bluetooth. Love to hear your thoughts.
Sounds like they may be referring to the update described in this thread Software update from Feb 2020? | PriusChat Check it out and see if it applies to your car. The download site isn't the most accurate, so be sure to check the PDF TSB that is linked in that thread.