Let's first try checking the notification settings in the app to ensure everything is set correctly:
To customize your the app notification settings, follow these steps:
Main Menu > Settings > Notifications > Notification Types
Make sure the Notifications are set to Normal.
If you are a Voxer Pro member, you can adjust Extreme Notification settings from this page as well.
New Message Alert should also be turned on.
We also recommend double checking the push notification settings on your Android device to ensure notifications are turned on for the app.
Try these steps:
Go to Settings > Sound & Notification > App Notifications. Select the app, and make sure that Notifications are turned on and set to Normal.
Make sure that Do Not Disturb is turned off.
If you performed all of these steps and your problem persists, we recommend ensuring that you've upgrade to the most recent version of the OS and Voxer available for your device.
Here is the link to some general troubleshooting tips and best practices. https://support.voxer.com/hc/en-us/articles/204330023-Troubleshooting-Tips