diff --git a/deploy/grafana/charon.json b/deploy/grafana/charon.json
index 79e4d88..0438ba4 100644
--- a/deploy/grafana/charon.json
+++ b/deploy/grafana/charon.json
@@ -570,15 +570,15 @@
         "allValue": ".*",
         "current": { "selected": true, "text": "All", "value": "$__all" },
         "datasource": { "type": "prometheus", "uid": "${datasource}" },
-        "definition": "label_values(charon_listener_blocks_received_total, chain)",
-        "description": "Chain label. Sourced from the listener counter (#328) — climbs the moment the websocket subscription delivers `new_heads`, so panels populate immediately on connect rather than waiting for the first pipeline tick.",
+        "definition": "label_values(charon_scanner_positions, chain)",
+        "description": "Chain label. Sourced from charon_scanner_positions which emits in both listen and replay modes (listener counter only emits in listen). Falls back to allValue=.* if the source is empty.",
         "hide": 0,
         "includeAll": true,
         "label": "Chain",
         "multi": true,
         "name": "chain",
         "options": [],
-        "query": { "query": "label_values(charon_listener_blocks_received_total, chain)", "refId": "StandardVariableQuery" },
+        "query": { "query": "label_values(charon_scanner_positions, chain)", "refId": "StandardVariableQuery" },
         "refresh": 2,
         "regex": "",
         "skipUrlSync": false,