On a sheet placed more than once, eeschema writes the Reference property from one instance only to avoid file churn. Copperpour's edit tools then refuse every symbol on that sheet as stale_target.
From the Grok pain-radar digests, Oct 31-Nov 1 2026 (Oct 31 9:41 PM ET through Nov 1 7:41 AM ET digests plus the Haitch overnight edition). Verified live 2026-11-01: issue/PR read; title and state confirmed.