The public Ogmios endpoint only serves a few concurrent ledger-state queries and returns 500 for the rest, so the Promise.all burst over the (now 19-wallet) list reliably failed several wallets every run. Query sequentially instead (full sweep ~2.5s) and retry each wallet once after 2s so a lone blip no longer posts a false "query failed" alert. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>