Here are some troubleshooting steps to fix a phone’s notification bar not working properly:

1. Restart the phone
2. Update to the most recent version of phone’s OS.
3. Verify notification settings are working properly.
4. Disable and then re-enable Do Not Disturb mode, if applicable.
5. Check for any damaged charging cables.
6. Inspect for any signs of water damage.
7. Test with another known working charger or battery if available.
8. Replace the battery.