Messages sent to a specific contact are being delivered to a different phone number

When I text one contact the number reverts to another contact. I have deleted both from my

iPhone 16 pro max and it still happens even with just the phone number. I have also deleted all messages from these specific numbers. It is only happening with these numbers. Both contacts are in the same household and use family sharing. I have been troubleshooting with Apple for about a week but they stopped attempting to set up troubleshooting. I checked both the other phones myself and can’t find any discrepancies that would explain why when you message one number it shows the other number and visa versa. Also even though one number shows the other number, the text still goes to the intended sender.

[Re-Titled by Moderator]