- Plesk Onyx for Linux
- One client in WHMCS is provisioned to two Plesk servers. Changing the email address on Plesk #1, then backing up the server and restoring it on Plesk #2 will duplicate the customer in Plesk > Customers.
- Same WHMCS client has different login name in Plesk > Customers > John > Edit contact info for Plesk #1 and Plesk #2.
This is Plesk bug #PPPM-9868, which is planned to be fixed in future product updates.
The root cause is that client details are not being updated by WHMCS module. WHMCS plugin feature request - https://github.com/plesk/whmcs-plugin/issues/35.
- Log into Plesk on both source and destination servers.
- Identify customer's username on destination server in Customers > John Doe > Change Login info > Username.
- Go to source server Customers > John Doe > Change Login info > Username and paste the same username.
- Backup from Tools & Settings > Backup Manager on the source server.
- Restore from Tools & Settings > Backup manager on the destination server.