[Windows Central Question]

Hi, my Facebook app was working fine until recently. First of all the sound notification stopped working, even though it had been working perfectly and was still showing as having a sound allocated to it. Then Facebook disappeared from the notifications in settings, now I don't get any notifications in the notification centre either! I have uninstalled and reinstalled countless times, as well as taking the battery out etc. Nothing works! VERY annoying! Any suggestions? Thanks.