Not receiving Facebook push notifications on galaxy s7

Hi all, Im having a major issue with Facebook. I cannot receive push notifications on my phone and in the lock screen. I have everything enabled as I have checked numours times. I have done nothing to my phone - I was messing around with it a few nights ago and maybe I disabled something... I really don't know. But it is vitally important that I get my push notifications working again asap. I'm going into the meteor shop tomorrow to see if anything can be done. Has anyone else had this problem with Samsung s7. The phone is only new and push notifications where working perfectly up until Saturday. When someone tags me or comments I don't see it unless I am in the fb app. Thanks and sorry for the long post