diff --git a/internal/gateway/server.go b/internal/gateway/server.go
index 9bd591b..1f54ce9 100644
--- a/internal/gateway/server.go
+++ b/internal/gateway/server.go
@@ -377,6 +377,9 @@ func (g *Gateway) handleModels(w http.ResponseWriter, r *http.Request) {
 }
 
 // ensureProbe triggers a live source probe at most once every 30s.
+// The probe runs asynchronously so a slow/stuck upstream never blocks the
+// status response — reachability data is eventually-consistent and the UI
+// polls /api/stats every 3s anyway, so the next refresh picks it up.
 func (g *Gateway) ensureProbe(ctx context.Context) {
 	g.probeMu.Lock()
 	due := time.Since(g.lastProbe) > 30*time.Second
@@ -384,9 +387,14 @@ func (g *Gateway) ensureProbe(ctx context.Context) {
 		g.lastProbe = time.Now()
 	}
 	g.probeMu.Unlock()
-	if due {
-		g.core.Registry().ProbeAll(ctx)
+	if !due {
+		return
 	}
+	go func() {
+		probeCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		defer cancel()
+		g.core.Registry().ProbeAll(probeCtx)
+	}()
 }
 
 // handleResetHealth (admin) clears the per-source backoff state so a fixed