3824088 - Error in logs: "Validating ParsedPhoneNumber//@Extension: Value"

When I save the Traveler Profile I see a generic error starting with:
"Concur saved your profile to the database but was unable to save it to the reservation system. Please contact SAP Concur support and share the following correlation ID code: XXXXXXX and here is the Request ID code for the error: XXXXXXX"

In GDS logs the following error can be found:

"NPDCTxxxxxxxxxxxxxxxx::Invalid XML (not compliant with Schema): Validating ParsedPhoneNumber//@Extension: Value "XXX-XXX-XXXX" contravenes the maxLength facet "10" of the type StringLength1to10. One or more validation errors were reported."

When I save the profile an error appears. In Service logs the following error is captured: "NPDCTxxxxxxxxxxxxxxxx::Invalid XML (not compliant with Schema): Validating ParsedPhoneNumber//@Extension: Value "XXX-XXX-XXXX" contravenes the maxLength facet "10" of the type StringLength1to10. One or more validation errors were reported." , KBA , CON-CA-USP , User Profile , Problem