> For the complete documentation index, see [llms.txt](https://support.whapi.cloud/help-desk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.whapi.cloud/help-desk/troubleshooting/why-does-my-iphone-show-an-endless-whatsapp-sync-notification-that-drains-the-battery.md).

# Why does my iPhone show an endless WhatsApp sync notification that drains the battery?

Sometimes a message can't be decrypted right away — when that happens, Whapi keeps trying to decrypt it in the background. On iPhone this retry cycle can surface as a persistent WhatsApp sync push notification that never clears, drains the battery, and gets in the way of normal phone use.

There are two ways to handle it:

1. Wait it out. In most cases the message eventually decrypts successfully on one of the retries, and the notification clears on its own. No action needed if the battery drain is tolerable in the meantime.
2. Disable the retry loop. If the notification persists too long, [turn off pdo\_sync](https://support.whapi.cloud/help-desk/account-and-whapi-channels/channel-settings-overview#other-params) for the channel:

{% code title="" overflow="wrap" %}

```json
{ "pdo_sync": false }
```

{% endcode %}

Default value: true.

{% hint style="warning" %}
**The value can turn back to `true`.** If you later update the channel settings without `pdo_sync` in the request (for example, change only the webhook), it returns to its default `true` and the notification comes back. Send `"pdo_sync": false` in every settings update request. Details and an example: [Channel Settings overview](https://support.whapi.cloud/help-desk/account-and-whapi-channels/channel-settings-overview).
{% endhint %}

The notification stopped and then came back? First check `pdo_sync` with [Get channel settings](https://whapi.readme.io/reference/getchannelsettings) — most likely it is `true` again.

{% hint style="warning" %}
Disabling pdo\_sync means some old messages that would have eventually decrypted on a later retry will stay undelivered instead.
{% endhint %}

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