sigsync.com has no AAAA records.
Apex domains cannot have CNAME records.
Microsoft
Domain verification
MS=ms38817724
ns-1325.awsdns-37.org
Amazon Web Services
Route 53
ns-1795.awsdns-32.co.uk
Amazon Web Services
Route 53
ns-228.awsdns-28.com
Amazon Web Services
Route 53
ns-795.awsdns-35.net
Amazon Web Services
Route 53
Zone apex
Start of authority
Email
Serial
1
Refresh
2h
Retry
15m
Expire
14d
Negative cache TTL
1d