I am a regular Facebook messenger user but sometimes I am going with facebook messenger not working. That I am trying a few methods to fix my issue. All those steps I have shared with you:
Update your phone
Uninstall and reinstall the Messenger app
Reset All Your Settings
Turn off Wi-Fi and turn it on again
Clear cache for Messenger
read also: https://ityug247.com/how-to-recover-deleted-messages-on-facebook-messenger/
How do I fix Messenger isn't responding?
Problem 1: Facebook Messenger Not Responding on Android/iPhone
Solutions 1: Force stop and clear cache (Android only)
Solutions 2: Reboot your device (iOS and Android)
Solutions 3: Uninstall and reinstall Facebook Messenger app.
Solutions 4: Use your browser (IE, Firefox, Chrome, Safari and so forth) for Messenger.
Regards,
Willjoe