Unanswered calls go to scam voicemail when using Apple CarPlay

Hi there, it appears my number has been spoofed. But only while using Apple CarPlay, while connected to CarPlay if someone phones me and I don’t answer it goes to “world lottery uk” which appears to be a prize type scam. They begin telling me I have won a prize etc. but when I’m not connected to CarPlay, if someone phones and I don’t answer. It goes to my own recorded voicemail, if I answer the call both when connected to CarPlay and not it answers as usual. I called my mobile carrier and they said there’s no cause for concern. They won’t be able to access my account. But I’m uncertain how to stop this happening while I’m connected to CarPlay, I’m self employed and drive for work so don’t want any potential new customers to think I’m a scam. Any ideas ? Thanks