diff --git a/src/entity-data-fetcher.js b/src/entity-data-fetcher.js
index 06b540f..db64a9a 100644
--- a/src/entity-data-fetcher.js
+++ b/src/entity-data-fetcher.js
@@ -129,7 +129,14 @@ export class EntityDataFetcher {
    * @returns {string} Selected activity state
    */
   _getActivityToUse(data, entityId, config) {
+    // Safety check for config
+    if (!config) {
+      this._log(`[Warning] No config provided to _getActivityToUse for ${entityId}. Defaulting to sensor.`);
+    }
+
     // Check if speed-based prediction is enabled
+    // We use optional chaining and strict equality to ensure we only enter this block
+    // if the user explicitly selected 'speed_predicted'
     if (config?.activity_source === 'speed_predicted') {
       if (data.speed) {
         // Use predicted activity and cache it for sticky behavior
@@ -145,6 +152,8 @@ export class EntityDataFetcher {
           return lastActivity;
         }
         // Fallback to unknown if no previous predicted activity
+        // IMPORTANT: We return 'unknown' here instead of falling back to sensor
+        // because the user explicitly requested speed-based prediction.
         this._log(`Activity for ${entityId}: unknown - speed null, no sticky value`);
         return 'unknown';
       }
@@ -162,6 +171,10 @@ export class EntityDataFetcher {
    * @returns {Object} Formatted entity data
    */
   prepareEntityData(config) {
+    if (!config) {
+      console.warn('[EntityDataFetcher] prepareEntityData called without config. Activity prediction may be incorrect.');
+    }
+
     const entityData = {};
 
     for (const [entityId, data] of Object.entries(this._entityCache)) {
diff --git a/src/map-badge-card.js b/src/map-badge-card.js
index 493c1ff..f043b88 100644
--- a/src/map-badge-card.js
+++ b/src/map-badge-card.js
@@ -187,7 +187,7 @@ class MapBadgeCard extends HTMLElement {
       this._messenger.sendData(this._pendingData);
       this._pendingData = null;
     } else if (this._dataFetcher.hasData()) {
-      this._messenger.sendData(this._dataFetcher.prepareEntityData());
+      this._messenger.sendData(this._dataFetcher.prepareEntityData(this._configManager.getConfig()));
     } else {
       this._fetchEntities();
     }
@@ -208,7 +208,7 @@ class MapBadgeCard extends HTMLElement {
 
         // If data is less than 30 seconds old, retry
         if (now - lastUpdate < 30000) {
-          this._messenger.sendData(this._dataFetcher.prepareEntityData());
+          this._messenger.sendData(this._dataFetcher.prepareEntityData(this._configManager.getConfig()));
           this._messenger.incrementRetryCount();
         }
       }