music does not get muted when listening to text messages while using carplay

I have an SE 2020 model running 18.2.1, carplay will not mute the sound source (radio, music from my phone's music app) when dictating texts that I have received, it won't mute the sound source when the navigator is giving me directions, it will mute the sound source when I initiate a phone call. I have a 2025 Toyota RAV4, with wireless carplay. I have discussed this with Toyota and they are pointing the finger at Apple, big surprise!. I'm skeptical because my phone worked with car play re muting audio sources during siri interactions in my old car (not a toyota) all the way through version 18.2. How can I absolutely confirm that this is a toyota software problem?