AttributeError: 'NoneType' object has no attribute 'split'

[sentry]

Sentry Issue: CARRIER-MONOLITH-DQD

AttributeError: 'NoneType' object has no attribute 'split'
  File "apps/carriers/tasks/notify_carrier_settings_updated_task.py", line 12, in notify_carrier_settings_updated_task
    NotifyCarrierSettingsChanged().execute(
  File "apps/carriers/use_cases/settings/notify_carrier_settings_updated.py", line 73, in execute
    email_address, phone_number = self._get_contact_info(carrier)
  File "apps/carriers/use_cases/settings/notify_carrier_settings_updated.py", line 23, in _get_contact_info
    phone_numbers = carrier_admin_connection.generic_user.phone_numbers.split(",")