Different versions of Android have different notification capabilities. If you are on Android Oreo, your system manages the notifications completely on its own through Notification Channels. For more info about this, please refer to this article.
If you are not on Oreo and you are not seeing notifications for new messages, here are a few places to start:
- Is Pulse SMS set as your default messaging app? It is designed to be the default.
- Does the test notification work? You can try it by going to Settings > Notification Customization and tapping "Test". If it does, you probably have snoozed the notifications or muted the conversation.
- If the test notification doesn't work, you have probably turned off notifications for Pulse SMS via a system-level setting. You will need to reenable Pulse SMS notifications by accessing your phone's Settings.