Siri not reading messages in CarPlay

Ok Brains Trust - 2019 VW Tiguan, Siri worked perfectly in CarPlay with my iPhone 6S, initially did so when I upgraded to an 8Plus, then randomly stopped reading my text messages and WhatsApp messages.

Siri responds to “Hey Siri”, accepts dictation of messages, but does not read them back, merely making the double-chime. She does the same double chime when I ask her to read my messages. As far as trouble-shooting I have:

1. Unpaired and repaired to CarPlay;
2. Used an Apple and other cord to try both;
3. VW have installed latest update for CarPlay;
4. I have checked all settings to ensure DND when driving etc is not switched off; and
5. I’ve ensured that my IOS is running on the current update.

Any suggestions as to what else I can try, as this is very inconvenient. Thanks in advance! ☺️