Background Refresh\Notifications do not work

Hello. IPhone 11 Pro here.

One month ago I stopped receiving notifications on my Iphone. I checked if some updates were available and I've updated Iphone to 16 IOS. This update didn't fix the issue. After that I've received several new updates during recent weeks, current version is 16.11.2, but this issue still exists.

The only application I sometimes receive notifications from is Instagram. For ALL other apps I need to open an app and only after that it starts refreshing it's content. I don't see anything on my lock screen and no sound is played.

I tried these steps:

1) Check that notifications are allowed on IOS level and for each particular app.

2) Check that Do not disturbed mode is off. Also, I've checked that this setting is not shared across all devices.

3) Check that Battery saving mode and Airplane mode are off.

4) Check that Background refresh setting is turned on for Wifi & Mobile Data.

5) I deleted all devices from apple account which I do not use anymore.

6) Reset Network settings.

7) Reset ALL settings.

8) Restart.

Neither of aforementioned steps helped.

Could you please help me?