Apple Maps goes back to portrait orientation after a long hands free call

I have an iPhone 14 with latest OS. I use a dash mount. I used a h/w GPS for years and prefer landscape orientation. It works great and is the most accurate in terms of location and ETA than everything I've used since 2004. When I make an extended hands free call, I lose the Maps screen and only see the phone screen. That's aggravating but not my main issue. If I'm on a short call the following does not happen. When on an extended call and hang up, the screen sometimes is locked and sometimes not. Either way once Maps is up and running again, Maps is in vertical orientation. Cycling between vertical and back to horizontal does not fix problem. Only restarting Maps from the screen and restarting the route lets the display go back to horizontal. I've done everything I know to do to unlock orientation. Perhaps this is setting I've missed. And while I'm here, is there a way to have the phone call display in the background and Maps on top while navigating and on a phone call at the same time? This is very frustrating. Thanks for any advice.