diff --git a/dashboard/js/grid.js b/dashboard/js/grid.js
index 503a175..803325b 100644
--- a/dashboard/js/grid.js
+++ b/dashboard/js/grid.js
@@ -107,6 +107,12 @@ const Grid = (() => {
     function update(agentId, metrics) {
         const entry = _agents.get(agentId);
         if (!entry) return;
+        // Conserver les valeurs lentes (disque, smart) quand le paquet ne les contient pas
+        if (entry.metrics) {
+            for (const k of Object.keys(entry.metrics)) {
+                if (metrics[k] == null && entry.metrics[k] != null) metrics[k] = entry.metrics[k];
+            }
+        }
         entry.metrics = metrics;
         const el = document.getElementById('tile-' + agentId);
         if (el) {