Given a resolv.conf that looks like
running local-unbound-setup produces a file /etc/unbound/forward.conf that looks like this:
# This file was generated by local-unbound-setup.
# Modifications will be overwritten.
Notably missing is a line on the end that should look like
If the ipv6-adress contains the sequence "::" the script works as expected.
This worked in FreeBSD 11.3, so we have a regression here.