It's v20.1 now, but the issue still there. it makes my downstream routers are not able to communicate with upstream devices/internet thru IPv6. Any progress on this?
https://forum.opnsense.org/index.php?topic=7719.msg36060#msg36060
I'm not entirely sure a thread from 2018 is still relevant today. You will have to provide more information on your individual case as the last 2 years span 4 major releases of changes...
Cheers,
Franco