No IPv6 connection outgoing (without manual intervention)

[STRUBartacus]

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Describe the bug

Initial situation:
WAN interface configured as DHCPv6
/56 prefix is issued by ISP
2 track interfaces and WAN are configured correctly with /64 from the PD
DHCP and RA are configured manually to be able to distribute DNS settings
Clients can configure themselves correctly with IPv6

Symptoms:
No outgoing IPv6 traffic is possible directly after configuring the OPNsense or after a restart.
A traceroute shows that the traffic is already stuck in the firewall.
However, the IPv6 addresses of the 3 interfaces can be pinged externally, and access to the OPNsense GUI is also possible.

Solution:
Deactivate and reactivate “Allow IPv6” under Interfaces - Settings
EDIT: I have to correct myself: Deactivating and reactivating the IPv6 support does not provide a reliable remedy. Sometimes it works via CLI option 11 and sometimes also by changing the WAN IPv6 parameters... I am lost....

To Reproduce

Reboot OPNsense

Expected behavior

A functional IPv6 connection after restart

Describe alternatives you considered

A CRON task which deactivates IPv6 after a restart and then reactivates it

Screenshots

Environment

Software version used and hardware type if relevant, e.g.:

OPNsense 25.1.1-amd64
FreeBSD 14.2-RELEASE-p1
OpenSSL 3.0.16
Supermicro A2SDi-4C-HLN4F
Intel Atom Processor C3558