Error message in iMessage for known number
When I try to send a message to a friend I get an error message from a bogus number saying "Error invalid number. Please resend using a valid 10 digit mobile number." I can sen to other contacts, and I've confirmed that the number I'm trying to send to is valid. I've typed the number in and used my Contact and get the same results.
MacBook Air 13″, macOS 13.2