Dns is not updating records
An example of a name server is the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet.
If is your DNS hosting provider, follow the steps in this article to verify your domain and set up DNS records for email, Skype for Business Online, and so on. To learn about webhosting and DNS for websites with Office 365, see Use a public website with Office 365.
If you’re having trouble with mail flow or other issues after adding DNS records, see Troubleshoot issues after changing your domain name or DNS records.
Before you use your domain with Office 365, we have to make sure that you own it.
An authoritative name server can either be a primary server (master) or a secondary server (slave).
A primary server for a zone is the server that stores the definitive versions of all records in that zone.