Shield disconnected Future in the MTProtoSender instead

telethon/client/updates.py

@@ -178,9 +178,7 @@ class UpdateMethods(UserMethods):
         while self.is_connected():
             try:
                 await asyncio.wait_for(
-                    asyncio.shield(self.disconnected, loop=self._loop),
-                    timeout=60,
-                    loop=self._loop
+                    self.disconnected, timeout=60, loop=self._loop
                 )
                 continue  # We actually just want to act upon timeout
             except asyncio.TimeoutError:

telethon/network/mtprotosender.py

@@ -214,7 +214,7 @@ class MTProtoSender:
         ends, either by user action or in the background.
         """
         if self._disconnected is not None:
-            return self._disconnected
+            return asyncio.shield(self._disconnected, loop=self._loop)
         else:
             raise ConnectionError('Sender was never connected')