Restore or set ZROOT boot environment as default

I had some problems upgrading to FREEBSD 14.0 from 13.2, and rollback
didn't quite fix it, and now the default FreeBSD boot environment of
zroot/ROOT/default and it won't boot anymore.

However, previous environments work:

#zfs list

zroot/ROOT/13.2-RELEASE-p9_2024-01-03_150553  1.68M   171G     11.0G  /
zroot/ROOT/14.0-RELEASE-p4_2024-01-03_135644  88.8M   171G     10.6G  /
zroot/ROOT/default                            38.3G   171G     10.5G  /

What's the proper way, for me to rollback so to the last working
environment:

zroot/ROOT/13.2-RELEASE-p9_2024-01-03_150553  1.68M   171G     11.0G  /

And have that as the boot default environment again?