@clbx: Were you using the Facebook app at the time, or accessing the site via a browser app? If you disable Wi-Fi and Mobile Data, do the notifications persist? In the meantime, please try pressing the Volume Down and Power buttons together until your phone restarts, as this will refresh the device and resolve any temporary issues.
@clbx: Thank you for clarifying. Further to my previous reply, please try heading to Settings > Apps > Facebook > Force stop > Storage > Clear cache > Clear data. If the notifications persist then please head to Settings > Battery and device care > Device protection > Scan phone, as this will check the device for any malware or suspicious activity.
