That has happened to me a lot long before 26. It happens because your entertainment system/radio, mistakenly identifies the map audio start as a phone call. I always have to hit the hang up button on the steering wheel.
Not happening on my three devices. As is not uncommon of "anypne's" updates, settings sometimes get changed which I suspect may be your problem. Overall, I quite like the new IOS and it certainly has not given me any thought of defecting.