Siri Getting The Phone Number Wrong In CarPlay

I recently installed a new car stereo with CarPlay. It worked well for a month but now when I reply to text messages, Siri is adding a different country code to the phone number. I don't why it would do that, especially since it is a reply to a message and not a new message.

Once she has read the message, she asks if I would like to reply. I say, yes and she asks what I would like to say. She then asks if I would like to send it and I say, yes. Later, when I look on my phone, Siri has created a new message to the same phone number but with a foreign country code in front of it (+1).

Does anyone know of this happening to anyone else or the reason it might be happening?