Facetime Inserting Country Code on Contacts
When using an iPhone 13 with up to date OS in US to attempt a FaceTime call to certain Contacts, intermittently, a Mexico country code is added in front of area code to all contacts in the list and the FaceTime call cannot complete (see. Removing SIM or logging out/in to AppleID temporarily solves but problem returns.
STEPS TAKEN
Tested on WiFi vs. Cellular - No difference
Contacts App read without additional code and phone calls are normal. (Contacts are on hosted exchange account)
FaceTime on MAC OS works correctly.
- Attempted to create new contacts - same error.
- Reset Network Settings
- Switched off and reloaded Exchange Contacts

- Backed up and Restored
- Swapped SIM
- Checked all country code settings
Other than swapping device or doing a clean install, what else could I try to resolve?
iPhone 13 Pro