Problem with push notifications on iOS

[SixthTR]

Checklist

- [☑️] I am reporting an issue in existing functionality that does not work as intended - [☑️] I've searched for existing GitHub issues

Description

Since the release of the iOS 15 beta version, Telegram has stopped receiving push notifications in a timely manner.

The way iOS works is that if the app is completely closed, a push notification comes in about a minute, but if it is open and minimized, the notification comes almost instantly.

However, over the last 2 years, Telegram has not sent notifications on iOS in a timely manner, making the user wait for up to a minute (and sometimes not even sending a notification at all), and this is something users with different iPhone models, iOS versions and Telegram clients face. Inside the app, however, notifications are timely.

By comparison, the macOS version of Telegram receives notifications almost instantly, not containing the problem of its iOS counterpart.

All other apps send push-notifications in a timely manner.

The problem lives on to this day on the latest current iOS 16.3.

P.S. A user once reported in a group that Pavel Durov had personally pointed out the problem and promised to fix it. P.P.S. Sometimes the badge counter on iOS updates instantly, but it is not followed by a push notification.

Expected Behavior

Push-notifications arrive in a timely manner instantly, like on all apps.

Actual Behavior

Push-notifications come with a delay of 10-120 seconds or don't come at all.

Steps to Reproduce

1. Just write to yourself from another account via a web client and calculate
2. Calculate the time it takes you to receive a push notification

Environment

Device: iPhone 13 Pro

iOS version: 16.3

App version: 9.4.2