Introduction In today’s mobile-first world, push notifications are essential for user engagement. However, managing push notifications across multiple devices and sessions can be challenging. In this blog post, we'll explore a common issue where users do not receive notifications after logging out and logging back in, especially on different devices or accounts. To ensure seamless notification delivery, we'll share a comprehensive solution using OneSignal, Flutter, and Django REST API. The Problem We encountered a significant issue where users were not receiving notifications consistently. Specifically, the problem arose when users logged out and logged in again on different devices or with other accounts. This inconsistency led to a poor user experience and reduced engagement. Root Cause AnalysisThe primary issue was the improper handling of OneSignal’s