Question: How to get TTS to work on AndroidThings MQTT Alarm Panel

[austwhite]

I am using the v1.5.0-beta.2 version and I am having an issue with TTS.
I can see the notification on the screen, can hear the beeps when pressing numbers, but I can't get the app to speak the MQTT message.
I know this is not under development now, but I was just wondering if you can guide me in what I may be doing wrong.
I am using a Raspberry Pi 3A, I have powered external speakers connected via 3.5mm audio. In settings -> notifications I have all 3 options ticked. AlarmState and MQTT message are not "spoken".

Thanks for any advice.