Siri adds the word No to beginning of messages and some commands in CarPlay

Have seen a couple of other posts here for the same thing with no real answer, thought I’d try my luck too. Have a 2021 model KIA Cerato, with wired CarPlay using an original Apple USB to lightning cable. An iPhone 11 with iOS 14.5.1. The firmware on the head unit is fully up to date. When I try to send new message or reply to a message in the standard messaging app, Siri adds the word NO to beginning of almost all messages. Siri also sometimes adds NO after asking me if I’d like to send the message and cancels it by itself. This is super frustrating.

I asked the car dealership about this and brought the car back in to test. He had an iPhone 11 iOS 14.4.2 and could not get it to fail using the same cable in my car. We tried another Cerato with the same head unit and again my iPhone failed and kept adding NO while his iPhone had no issue and we could not get it to fail once. I also later tried with my work iPhone 11 on iOS 14.5.1 and it also has the same issue and adds NO in front of messages. Have also tried another cable, no difference. Only difference to the dealers phone is the iOS version but this exact same issue has been posted previously here some time ago so not sure it is iOS version related.

This only happens in the car using CarPlay and not when using Siri just on the phone stand-alone.

if anyone has any idea, please let me know!

thanks in advance,