Symptoms
After changing the primary domain name of an account, the A record of an addondomain is updated to point to the IP of the main domain.
Description
This may be related to the addon domain's existing records in the primary domains zone file.
We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-50406. Follow this article to receive an email notification when a solution is published in the product.
Workaround
Manually update the A record of the addon domain to point to the desired IP after the primary domain name change.