All day I have been buying items from NPC shops I haven't received the site event for it once all day.

I just got it a bit ago so it's definitely still working. It's random chance though so maybe you were just unlucky?

I ALWAYS get it a few times a day and today nothing. this has never happened

I usually get it once or twice a day as well but there was one day where I did all my quests and some extra shopping and I never got the buff. It's just luck, really. Maybe try restocking for a while and see if you can get it to work?