If the NTP server is on the Public interface of the 3000, then you need to add Rules to the Public filter to allow NTP traffic in/out. By default the Public filter only allows IPSec/PPTP/L2TP/NAT-T type traffic in.
Check out the other rules under Config - System - Policy Mgmt - Rules for the format, and then create new ones for NTP in/out. Then add them to the Public filter under the Filter section and "Assign Rules to Filter"
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...