diff --git a/src/App.tsx b/src/App.tsx
index 663a643..afb2274 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -135,18 +135,20 @@ function AppInner() {
   // packet analyzer shown as a modal over the node panel (clicking a node's observation row)
   const [overlayPacketHash, setOverlayPacketHash] = useState<string | null>(null);
 
+  // short staleTime: observations keep accruing, so reopening the analyzer should show them
+  // instead of a snapshot frozen at first open
   const { data: analyzerDetail, isLoading: analyzerLoading } = useQuery({
     queryKey: ["packet-detail", analyzerHash],
     queryFn: () => getPacketDetail(analyzerHash!),
     enabled: !!analyzerHash,
-    staleTime: Infinity,
+    staleTime: 30_000,
   });
 
   const { data: overlayPacketDetail, isLoading: overlayPacketLoading } = useQuery({
     queryKey: ["packet-detail", overlayPacketHash],
     queryFn: () => getPacketDetail(overlayPacketHash!),
     enabled: !!overlayPacketHash,
-    staleTime: Infinity,
+    staleTime: 30_000,
   });
 
   const handleAnalyze = useCallback((hash: string | null) => {
@@ -168,6 +170,12 @@ function AppInner() {
     setSearchParams((prev) => {
       const next = new URLSearchParams(prev);
       next.set("tab", tab);
+      // stats sub-state shouldn't haunt the URL on other tabs
+      if (tab !== "Stats") {
+        next.delete("statsTab");
+        next.delete("observerId");
+        next.delete("range");
+      }
       return next;
     });
   };
diff --git a/src/api/ws-manager.ts b/src/api/ws-manager.ts
index 981264b..93f71a4 100644
--- a/src/api/ws-manager.ts
+++ b/src/api/ws-manager.ts
@@ -176,7 +176,7 @@ export class WsManager {
         this.sendSubscribe();
         if (isReconnect) {
           // we were dark during the outage — synthesize a lag notice so live views heal the gap
-          const notice: WsLagged = { v: 1, type: "lagged", droppedCount: 0, since: this.lastEventTimestamp, lastObservationId: 0 };
+          const notice: WsLagged = { v: 1, type: "lagged", droppedCount: 0, since: this.lastEventTimestamp };
           for (const handler of this.laggedHandlers) {
             handler(notice);
           }
diff --git a/src/components/ErrorBoundary.tsx b/src/components/ErrorBoundary.tsx
index 87f053a..bebdabc 100644
--- a/src/components/ErrorBoundary.tsx
+++ b/src/components/ErrorBoundary.tsx
@@ -19,15 +19,18 @@ export class ErrorBoundary extends Component<Props, State> {
   render() {
     if (this.state.error) {
       if (this.props.fallback) return this.props.fallback;
+      // React.lazy caches a rejected import, so remounting can't recover a failed chunk load
+      // (e.g. a deploy swapped the hashed assets out from under us) — only a real reload can
+      const chunkFailure = /dynamically imported module|Loading chunk|error loading/i.test(this.state.error.message);
       return (
         <div className="flex flex-col items-center justify-center flex-1 gap-3 p-8 text-text-dim">
           <p className="text-sm font-mono">Something went wrong rendering this view.</p>
           <button
             type="button"
             className="text-xs font-mono underline cursor-pointer text-primary"
-            onClick={() => this.setState({ error: null })}
+            onClick={() => (chunkFailure ? window.location.reload() : this.setState({ error: null }))}
           >
-            try again
+            {chunkFailure ? "reload" : "try again"}
           </button>
         </div>
       );
diff --git a/src/features/map/MapSettingsPanel.tsx b/src/features/map/MapSettingsPanel.tsx
index 54ce2a9..5b88cf0 100644
--- a/src/features/map/MapSettingsPanel.tsx
+++ b/src/features/map/MapSettingsPanel.tsx
@@ -38,12 +38,15 @@ export function MapSettingsPanel({
     return stored === null ? !isMobile : stored === "true";
   });
 
-  const toggle = () =>
-    setOpen((v) => {
-      const next = !v;
+  const toggle = () => {
+    const next = !open;
+    setOpen(next);
+    try {
       localStorage.setItem(OPEN_STORAGE_KEY, String(next));
-      return next;
-    });
+    } catch {
+      // private mode / quota — the toggle still works, just not persisted
+    }
+  };
 
   return (
     <div className="absolute top-3 left-3 z-10 w-60 max-w-[calc(100vw-1.5rem)] bg-bg-raised border border-border rounded-md shadow-lg overflow-hidden font-mono">
diff --git a/src/features/map/MapView.tsx b/src/features/map/MapView.tsx
index 8512160..6e7d7e3 100644
--- a/src/features/map/MapView.tsx
+++ b/src/features/map/MapView.tsx
@@ -96,7 +96,7 @@ export function MapView({ wsManager, selectedNodeId, onSelectNode }: MapViewProp
   const { containerRef, mapRef, isReady, error } = useMapLibre(styleId, fitPoints, handleStyleError);
   const isDark = resolveMapStyle(styleId).dark; // drives marker theming + maplibre control chrome
 
-  useMapNodes(mapRef, isReady, geojson, isDark, themeKey, clustered, onSelectNode, selectedNodeId);
+  useMapNodes(mapRef, isReady, geojson, isDark, themeKey, clustered, onSelectNode, selectedNodeId, `${regionKey}:${typeFilter}`);
 
   return (
     <div className="relative flex flex-1 min-h-0">
diff --git a/src/features/map/useMapNodes.ts b/src/features/map/useMapNodes.ts
index 4f1998f..545811d 100644
--- a/src/features/map/useMapNodes.ts
+++ b/src/features/map/useMapNodes.ts
@@ -98,8 +98,12 @@ export function useMapNodes(
   clustered: boolean,
   onSelectNode: (id: string) => void,
   selectedNodeId: string | null,
+  // identity of the dataset (region + type filter); an open spiderfy fan closes when it changes,
+  // since its leaves were drawn from the previous dataset
+  resetKey = "",
 ) {
   const geojsonRef = useRef(geojson);
+  const spiderRef = useRef<Spiderfy | null>(null);
   const onSelectNodeRef = useRef(onSelectNode);
   const selectedNodeIdRef = useRef(selectedNodeId);
   const appliedClusteredRef = useRef(clustered);
@@ -338,6 +342,7 @@ export function useMapNodes(
       spiderLeavesLayout: SPIDER_LEAVES_LAYOUT,
     });
     spider.applyTo(NODES_CLUSTER_LAYER_ID);
+    spiderRef.current = spider;
     // @nazka/map-gl-js-spiderfy registers its cluster-click handler inside a one-shot map.once("idle").
     // With 3D terrain that idle often doesn't fire before this effect re-runs, so the handler never
     // attaches (clusters look unclickable) or attaches late as an orphan after cleanup. Run that
@@ -384,6 +389,7 @@ export function useMapNodes(
         map.off("mouseenter", layer, setPointer);
         map.off("mouseleave", layer, clearPointer);
       }
+      spiderRef.current = null;
       try {
         spider.unspiderfyAll();
       } catch {
@@ -392,4 +398,13 @@ export function useMapNodes(
     };
     // themeKey is a dep so spiderfy rebuilds and its legs + leaf icons pick up the new palette
   }, [mapRef, isReady, clustered, themeKey]);
+
+  // close any open fan when the dataset identity changes — its leaves no longer exist
+  useEffect(() => {
+    try {
+      spiderRef.current?.unspiderfyAll();
+    } catch {
+      /* map may already be removed */
+    }
+  }, [resetKey]);
 }
diff --git a/src/features/stats/ObserverTab.tsx b/src/features/stats/ObserverTab.tsx
index 625b6ec..dd8823c 100644
--- a/src/features/stats/ObserverTab.tsx
+++ b/src/features/stats/ObserverTab.tsx
@@ -29,7 +29,12 @@ function ObserverList({
 }) {
   const { iatas, regionKey } = useRegion();
   const [query, setQuery] = useState("");
-  const q = query.trim();
+  // debounce so the server-side lookup fires once per pause, not once per keystroke
+  const [q, setQ] = useState("");
+  useEffect(() => {
+    const id = setTimeout(() => setQ(query.trim()), 250);
+    return () => clearTimeout(id);
+  }, [query]);
   const searching = q.length > 0;
 
   // default: top observers by activity (with count + activity bar). Searching swaps to a server-side
@@ -63,7 +68,10 @@ function ObserverList({
       />
       <div className="flex flex-col gap-0.5">
         {loading && <div className="py-6 text-center font-mono text-[11px] text-text-dim">{searching ? "Searching…" : "Loading…"}</div>}
-        {!loading && rows.length === 0 && (
+        {searching && search.isError && (
+          <div className="py-6 text-center font-mono text-[11px] text-danger">Search failed</div>
+        )}
+        {!loading && !(searching && search.isError) && rows.length === 0 && (
           <div className="py-6 text-center font-mono text-[11px] text-text-dim">{searching ? "No matches" : "No observers"}</div>
         )}
         {rows.map((r) => {
diff --git a/src/types/ws.ts b/src/types/ws.ts
index 73287ed..3a0590a 100644
--- a/src/types/ws.ts
+++ b/src/types/ws.ts
@@ -67,9 +67,9 @@ export interface WsObserverStatus {
     iata: string;
     online: boolean;
     radio?: string; // compact "freq,bw,sf" string
-    scopes: string[];
-    batteryMv: number | null;
-    uptimeSeconds: number | null;
+    scopes: string[] | null; // a nil slice marshals to null
+    batteryMv?: number; // omitempty — absent when unknown (0)
+    uptimeSeconds: number;
     lastStatusAt: number;
   };
 }
@@ -107,7 +107,7 @@ export interface WsLagged {
   type: "lagged";
   droppedCount: number;
   since: number;
-  lastObservationId: number;
+  lastObservationId?: number; // declared in the protocol but not sent today
 }
 
 export interface WsError {