DNS Clustering Problem

[eduardop]

I'm having a problem with DNS Cluster.
I have two servers running Cpanel
I trying to make DNS cluster from NS1 to NS2 to keep them sync.
I setup DNS cluster on NS1 and it updates NS2 when it is a change.
Now I found when I make a change on NS2 it also writes on NS1.
Why is it happening?
On NS2 DNS Cluster is disabled.
Thanks for your comments

[SB-Nick]

Did you try setting up NS2 as Stand alone?

[eduardop]

Did you try setting up NS2 as Stand alone?

If I set up NS2 as Stand Alone NS1 does not write to NS2

[eduardop]

also I get this message when I add a server to my main whm server
The trust relationship has been established from the remote server to this server as well.
Is this ok?

[explorer]

I think that is correct and the idea behind clustering is that the two servers are identical regardless of the one that is updated. So I would have thought ns1 should update ns2 and vice versa!