In order to change DNS servers, I recommend running a test of the target zone before ordering the change.
The test can be performed using the page below
https://zonemaster.net/en/run-test
Click on "Show options"> Enter the names of the target DNS servers and the domain name and click "Run test"
The test result cannot show critical errors with the zone configuration, and the zone itself must be active at the time of the change.
Issues related to the appropriate configuration of the target DNS zone should be consulted with the administrator of these servers.
Below are some of the conditions that must be met at the time of change:
- On the side of the DNS servers to which the change is requested, there must be a DNS zone for this domain
- The names of the servers to which the change is requested must be the same as the names of the servers indicated in the NS records in this zone
- The servers must respond at the time of change
- The full set of servers must be provided, i.e. if 3 servers are indicated in the NS records, the change must be requested for all 3 servers
In such a case, please contact the DNS server operator to verify whether these conditions have been met.