Reminder issues -S Planner-

Hello everyone and nice to be here, this is my very first post

I have almost the worst memory any young adult can have - so I depend on S Planner to remind me of my different daily tasks.

When I Add an even (or a task) on S Planner, there's an option that allows you to choose when to be reminded of this event or task. I always turn it on and set it to remind me 15 mins before, yet it never reminded me of any task.

Am I missing out on something?

Thanks