diff --git a/app/Jobs/Machine/ProcessHeartbeat.php b/app/Jobs/Machine/ProcessHeartbeat.php
index f513fdc..1ff0ca0 100644
--- a/app/Jobs/Machine/ProcessHeartbeat.php
+++ b/app/Jobs/Machine/ProcessHeartbeat.php
@@ -64,13 +64,17 @@ class ProcessHeartbeat implements ShouldQueue
         // 2. 韌體版本比對 (有改才傳，有改才記)
         if (isset($this->payload['firmware_version'])) {
             $fv = (string) $this->payload['firmware_version'];
-            if (!isset($oldState['firmware_version']) || (string)$oldState['firmware_version'] !== $fv) {
+
+            // 優先從快取取舊版本，若無則從資料庫取
+            $oldVersion = $oldState['firmware_version'] ?? $machine->firmware_version;
+
+            if ((string)$oldVersion !== $fv) {
                 \App\Jobs\Machine\ProcessStateLog::dispatch(
                     $machine->id,
                     $machine->company_id,
                     "Firmware updated to :version",
                     'info',
-                    ['version' => $fv, 'old' => $oldState['firmware_version'] ?? 'Unknown']
+                    ['version' => $fv, 'old' => $oldVersion ?? 'Unknown']
                 );
             }
             $updateData['firmware_version'] = $fv;
@@ -87,21 +91,11 @@ class ProcessHeartbeat implements ShouldQueue
             $tempLogCacheKey = "machine:{$this->serialNo}:last_temp_log";
             $lastLogEntry = \Illuminate\Support\Facades\Cache::get($tempLogCacheKey);
 
-            $shouldLog = false;
-            if (!$lastLogEntry) {
-                $shouldLog = true;
-            } else {
-                $lastValue = (int) $lastLogEntry['value'];
-                $lastAt = \Carbon\Carbon::parse($lastLogEntry['at']);
+            // 統一邏輯：優先從快取取值，若無則從資料庫取
+            $oldTemp = isset($lastLogEntry['value']) ? (int)$lastLogEntry['value'] : $machine->temperature;
 
-                // 條件 A: 只要溫度與上次記錄不同就記錄 (整數比對)
-                if ($temp !== $lastValue) {
-                    Log::debug("ProcessHeartbeat: Temperature changed from {$lastValue} to {$temp}. Triggering log.");
-                    $shouldLog = true;
-                }
-            }
-
-            if ($shouldLog) {
+            if ($temp !== (int)$oldTemp) {
+                Log::debug("ProcessHeartbeat: Temperature changed from {$oldTemp} to {$temp}. Triggering log.");
                 \App\Jobs\Machine\ProcessStateLog::dispatch(
                     $machine->id,
                     $machine->company_id,
@@ -109,13 +103,13 @@ class ProcessHeartbeat implements ShouldQueue
                     'info',
                     ['temp' => $temp]
                 );
-
-                // 更新快取，保留 7 天
-                \Illuminate\Support\Facades\Cache::put($tempLogCacheKey, [
-                    'value' => $temp,
-                    'at' => now()->toDateTimeString()
-                ], 604800);
             }
+
+            // 無論是否有變動，都更新/延長快取壽命，確保快取資料存在
+            \Illuminate\Support\Facades\Cache::put($tempLogCacheKey, [
+                'value' => $temp,
+                'at' => now()->toDateTimeString()
+            ], 604800);
         }
 
         // 更新快取