Apple CarPlay - no sound on car media system when making call

There is no sound when making a phone call on Apple Car Play on my Toyota Landcruiser 300 series. I have looked at the previous responses on the Apple Community and most of the focus is on the actual Apple device not the Apple CarPlay software on the car/ SUV. This has just started in last week. I have the latest software on my IPhone 15 Pro Max, I have swapped out USB cables between phone and car connection still same issue, I have also “forget car” in Car play and re established connection again, same issue. Toyota are also saying it’s an Apple issue not a toyota issue, so need HELP please.