diff --git a/static/index.html b/static/index.html
index e541781..0b6c411 100644
--- a/static/index.html
+++ b/static/index.html
@@ -810,7 +810,6 @@
             ctx.fillText((Number(knValue) || 0).toFixed(1) + ' ' + UNIT_FORCE, cx, cy + 58);
         }
 
-        // FIX: update digital display HTML elements (only visible when show_gauge_digital: true)
         function updateDigitalDisplay(side, percent, kn) {
             if (!SHOW_GAUGE_DIGITAL) return;
             const el = document.getElementById('digital-' + side);
@@ -1132,6 +1131,20 @@
             } catch (err) { console.warn('UI revision check error:', err); }
         }
 
+        function computeStaleFromPayload(d, connected) {
+            if (!connected) return false;
+            if (typeof d.stale === 'boolean') return d.stale;
+            if (!d.last_update) return false;
+
+            const lastTs = new Date(d.last_update).getTime();
+            if (isNaN(lastTs)) return false;
+
+            const serverNowTs = d.server_time ? new Date(d.server_time).getTime() : Date.now();
+            if (isNaN(serverNowTs)) return false;
+
+            return (serverNowTs - lastTs) > STALE_MS;
+        }
+
         async function fetchLiveData() {
             try {
                 const res = await fetch('/api/data', { cache: 'no-store' });
@@ -1148,12 +1161,7 @@
                 const bias        = Number(d.bias_percent)     || 0;
                 const leftKN      = Number(d.sila_l_kn)        || 0;
                 const rightKN     = Number(d.sila_r_kn)        || 0;
-
-                let stale = false;
-                if (connected && d.last_update) {
-                    const lastTs = new Date(d.last_update).getTime();
-                    if (!isNaN(lastTs)) stale = (Date.now() - lastTs) > STALE_MS;
-                }
+                const stale       = computeStaleFromPayload(d, connected);
 
                 setConnectionIndicator(connected, stale);
                 setProcessVisualState(connected && !stale);
@@ -1171,8 +1179,6 @@
 
                 applyChannelState('l', leftPercent);
                 applyChannelState('r', rightPercent);
-
-                // FIX: update digital HTML displays (was missing in original)
                 updateDigitalDisplay('l', leftPercent, leftKN);
                 updateDigitalDisplay('r', rightPercent, rightKN);
 
@@ -1188,7 +1194,6 @@
                 updateSummaryBar(false, false, 0, 0, 0);
                 updateMachineVerdict(false, false, 0, 0, 0);
                 updateAlarmBanner(0, 0, 0, false, false);
-                // FIX: reset digital displays on error
                 updateDigitalDisplay('l', 0, 0);
                 updateDigitalDisplay('r', 0, 0);
             }
@@ -1426,4 +1431,4 @@
         };
     </script>
 </body>
-</html>
\ No newline at end of file
+</html>