Push notifications for online user

I’ve added push notifications to my iOS app, when I try to register device token for certain user via Platform API v3 (Add a registration or device token | Chat Platform API | Sendbird Docs) I receive push notifications only when I’m offline, when the app is open push notifications are not delivered. But when I register device token in my app with iOS Sendbird SDK (SendbirdUIKit v3.3.0) everything works fine and I can get push notifications even if I’m online. Why the behaviour is different?

[UIKit Version]
Platform API v3 for backend.
SendbirdUIKit v3.3.0 for iOS.

[Reproduction Steps]

  1. Register device token on iOS.
  2. Send device token to backend.
  3. Register device token for this user via Platform API.
  4. Send message to this user when he is online and offline.


[Current impact]
It’s not critical cause we can register device token on iOS but why the behaviour is different when I try to register device token from backend.