userdel rewrites /etc/subuid and /etc/subgid, and like every shadow-utils database write it leaves the previous contents behind in a dash-suffixed backup. The scrub removed four of the six backups those tools produce, so the retained @factory baseline still named the previous owner in /etc/subuid- and /etc/subgid- along with their subordinate ID range. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>