diff --git a/channels/telegram_channel.py b/channels/telegram_channel.py
index c94a17a..dde9974 100644
--- a/channels/telegram_channel.py
+++ b/channels/telegram_channel.py
@@ -82,8 +82,9 @@ class TelegramChannel(BaseChannel):
         """Endlos-Polling im Hintergrund."""
         try:
             await self._app.updater.start_polling(allowed_updates=["message"])
-            # Warte bis gestoppt
-            await self._app.updater.idle()
+            # In PTB v20+ läuft der Updater als eigener asyncio-Task weiter –
+            # wir warten hier einfach, bis der Task abgebrochen wird.
+            await asyncio.Event().wait()
         except asyncio.CancelledError:
             pass
         except Exception as exc:
diff --git a/tasks/receiver.py b/tasks/receiver.py
index 4ec1ea9..f5f0efc 100644
--- a/tasks/receiver.py
+++ b/tasks/receiver.py
@@ -21,14 +21,15 @@ def build_scheduler(whatsapp: "WhatsAppChannel") -> AsyncIOScheduler:
 
     _scheduler = AsyncIOScheduler(timezone="UTC")
 
-    # WhatsApp-Polling alle 5 Sekunden
+    # WhatsApp-Polling alle 10 Sekunden (coalesce=True überspringt verpasste Läufe)
     _scheduler.add_job(
         _poll_whatsapp,
-        trigger=IntervalTrigger(seconds=5),
+        trigger=IntervalTrigger(seconds=10),
         id="whatsapp-poll",
         name="WhatsApp incoming messages",
         max_instances=1,
         coalesce=True,
+        misfire_grace_time=5,
     )
 
     return _scheduler