We did recently improve how notifications are delivered on Android, about 1-2 weeks ago. Keep an eye on if you are still having issues, I hope the delay is resolved.
The mobile app does a "jump to the first unread message" by default, which is the same behavior the web app follows.
If you don't want to read through all the messages in the current stream you can press "Mark as read" and then the app will be jumping you to the latest messages.
Would that improve your navigation flow in the app?