Currently we have 5 Name servers, for redundancy.
Those nameservers are placed in different contries than the webserver, and therefore the webserver are not a DNS server.
The problem is then, whenever we try to setup the nameserver under Server Configuration »Basic cPanel & WHM Setup (At the button) there's only 4 fields.
We have solved this by adding the NS record and A record, to the 5'th nameserver ourself, to the DNS template.
But this is showing the the ns05 in their advanced dns records, where the other 4 nameservers are hidden.