diff --git a/module/device/connection.py b/module/device/connection.py
index 2d29d0ab9..2bc838e70 100644
--- a/module/device/connection.py
+++ b/module/device/connection.py
@@ -273,15 +273,20 @@ class Connection(ConnectionAttr):
             return True
         return False
 
+    @cached_property
+    def nemud_app_keep_alive(self) -> str:
+        res = self.adb_getprop('nemud.app_keep_alive')
+        return res
+
     @retry
     def check_mumu_app_keep_alive(self):
         if not self.is_mumu_family:
             return False
 
-        res = self.adb_getprop('nemud.app_keep_alive')
+        res = self.nemud_app_keep_alive
         logger.attr('nemud.app_keep_alive', res)
         if res == '':
-            # Empry property, might not be a mumu emulator or might be an old mumu
+            # Empty property, probably MuMu6 or MuMu12 version < 3.5.6
             return True
         elif res == 'false':
             # Disabled
diff --git a/module/device/connection_attr.py b/module/device/connection_attr.py
index cfa78a927..622020960 100644
--- a/module/device/connection_attr.py
+++ b/module/device/connection_attr.py
@@ -127,7 +127,12 @@ class ConnectionAttr:
     def is_mumu_family(self):
         # 127.0.0.1:7555
         # 127.0.0.1:16384 + 32*n
-        return self.serial == '127.0.0.1:7555' or self.serial.startswith('127.0.0.1:16')
+        return self.serial == '127.0.0.1:7555' or self.is_mumu12_family
+
+    @cached_property
+    def is_mumu12_family(self):
+        # 127.0.0.1:16384 + 32*n
+        return len(self.serial) == 15 and self.serial.startswith('127.0.0.1:16')
 
     @cached_property
     def is_emulator(self):