The operator: problem cards "can disappear so quickly". Each router was graded on its latest scrape, so a 4xx share near the 1% cutoff crossed it on one scrape and fell back on the next. recent_window reads every router's last 15 minutes in one query, the error shares weighted by traffic; grade_routers uses it on the page and the dashboard widget, and the why says "over the last 15 min". traefik_config_last_reload_success is the Unix time of the last good reload, not a 0/1 flag, so the tile said "Reload failed" on every scrape. traefik_005 stores it as config_last_reload_at, and the tile reads "Config reloaded 3m ago". The router index also carries the 4xx share. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>