Carplay cuts out radio then does not go back

When I have the radio (or sirius xm, whatever) playing and I'm using google maps through Carplay, and I have google maps running on an an iphone 6s, when the voice audio cuts in to give a direction, google maps app cuts in and lets me hear the direction, as I would expect. However, then it does not yield back the audio to the radio. I have to manually push the radio button to start hearing the "radio" again. Then next time there's a direction, Carplay correctly cuts in again, but then again I have to manually push the radio button again to hear it. This is an annoying bug and not at all the way I want it to work. I would really appreciate if they could fix this or if someone would give a simple solution. Thank you.