It seems to me that you are having some sort of problems with replication and/or configuration between ns16.zoneedit.com and ns9.zoneedit.com. My domain registrar send an e-mail this morning saying my DNS service failed their automatic testing. When checking the results myself, noticed that there are multiple fails and warnings (see below). Will you be fixing this any time soon or should I consider moving my DNS records to some other service provider?
Fail 1: Zone data version
The name servers do not have the same version of the DNS data. Please make sure that all name servers get their zone record updated to the latest version.
Name server
IP address
Serial
ns16.zoneedit.com
104.236.6.173
1425593323
ns9.zoneedit.com
23.27.48.60
1418142714
Fail 2: Admin email
Nameservers have different admin email addresses in their SOA records
Warning 1: Master name server
The master nameserver is not one of the public nameservers for the zone: dns0.zoneedit.com
Warning 2: Reverse records (PTR)
At least one name server is missing a reverse record which points back to the hostname.
Name server
IP address
Reverse records
ns16.zoneedit.com
104.236.6.173
pdns1.zoneedit.com
ns9.zoneedit.com
23.27.48.60
ns9.zoneedit.com
Fail 1: Zone data version
The name servers do not have the same version of the DNS data. Please make sure that all name servers get their zone record updated to the latest version.
Name server
IP address
Serial
ns16.zoneedit.com
104.236.6.173
1425593323
ns9.zoneedit.com
23.27.48.60
1418142714
Fail 2: Admin email
Nameservers have different admin email addresses in their SOA records
Warning 1: Master name server
The master nameserver is not one of the public nameservers for the zone: dns0.zoneedit.com
Warning 2: Reverse records (PTR)
At least one name server is missing a reverse record which points back to the hostname.
Name server
IP address
Reverse records
ns16.zoneedit.com
104.236.6.173
pdns1.zoneedit.com
ns9.zoneedit.com
23.27.48.60
ns9.zoneedit.com