Phone Number Redaction is enabled for your account. Sticky Sender is not compatible with Phone Number Redaction and should be disabled.
Possible Causes
You have Sticky Sender enabled on your Messaging Service. Sticky Sender requires Twilio to save the non-redacted phone numbers of recipients, and is incompatible with Phone Number Redaction.
Possible Solutions
Disable Sticky Sender on your Messaging Services using the Twilio Console or the REST API.
If Sticky Sender functionality is needed, implement this functionality in your own application.