The incoming SMS alerts are sent to unintended recipient.
The following are the possible causes for the issue:
•Data indexing issue – There are more than 200,000 records on which the query runs. Therefore the incoming SMS is assigned to the OAuth user.
•Notification settings are not configured correctly.
•The Previous message lookup did not happen.
•Incoming SMS was received from an unknown number.
•User does not have permissions for updating the Previous Lookup or the related SMS History
Do the following to resolve the issue:
•Index all mobile fields. Refer to the document in the link provided below for more details on Field Indexing.
•Configure all notifications correctly. For more details, refer the section on Configure Incoming Notifications under Sender ID and Assignment in the SMS-Magic Converse Guide for Salesforce Admin: