Resolve otc domain via return ServFail

hello, We now resolve the domain name and via, it return ServFail , but via or other public dns it 's ok .
we do the command "dig +short CHAOS TXT id.server @ " on the problem nodes , it displays the “BUD” , we also test the resolving on Germany and China nodes , the result is normal.
Please help to check it on BUD cluster, thanks

One potential issue could be the primary server listed in your SOA record. It currently mentions whereas it should probably point to either one of your actual nameservers.

Cant say for sure yet that this will be the issue.