How to keep Google Maps on screen when making a bluetooth phone call?

This question has been asked before but never seems to have been answered so I’ll try again. Until recently I had an iPhone 13. I drive a coach and use google maps for navigation. Quite often my boss will call me (or my wife). With the 13 a banner would come up at the top of my navigation and I’d take (or make) the call whilst still watching and listening to navigation. I recently bought an iPhone 15 pro and it’s all changed and become frustrating. I’m watching my navigation and a call comes in when I touch my Bluetooth earpiece to answer the call, the call swipes in front of my navigation, taking up the whole screen. At the end of the call it goes to Home Screen or WhatsApp chat screen and doesn’t revert back to navigation so I have to stop driving and swipe the maps screen back in front as I can’t do that whilst driving. Also. I’ve noticed when doing the same in the car via CarPlay if listening to the radio or other media, it goes silent when I make or receive a call. At the end of the call, silence, I have to switch the radio back on or press play for other media. It used to happen automatically. I wish Apple would stop fiddling with things like this. Anyone know how to keep my navigation on top and the call as just a banner, or how to make radio come back on after a call without having to press the button? The second one isn’t a huge problem but it’s a step back. The navigation is a complete pain having to stop. If I don’t pull in and do it, one of my passengers will undoubtedly grass me up for touching my phone while driving.