Siri always sending messages even when I say ‘change’

I only use Siri for speech-to-text messaging while I’m driving with my Apple CarPlay, Stinger Heigh10 radio and a wireless airplay box. When I speak a text to send, Siri will read back my message and ask ‘send it, or change?’ And no matter what I say it will send the message. Even if I tap the ‘change’ selection on the screen Siri replies ‘Done!’ and sends the message. How can I fix this ‘feature’ back to normal?