The bundle was shipping 80.conf (HTTP-to-HTTPS redirect + acme-challenge
alias) to /etc/nginx/sites/80.conf, but nginx.conf only `include`s
/etc/nginx/sites-enabled/* (which is a symlink to sites-available).
The file was orphaned — no node had a working port-80 listener.
Move the destination to /etc/nginx/sites-available/80.conf so the
existing sites-enabled symlink picks it up. The /etc/nginx purge will
clean up any stale /etc/nginx/sites/80.conf on existing hosts.