Why is my planner in s7 not notifying me of events

[AC Question]

I have set a reminder and checked that notifications are on in the settings. I have had some events notify and others not but am not doing anything different as far as I can tell

 

[Sleepywolf]

I am experiencing the same issue with the S7 edge. I've missed important events because no notification has occured when it should have. It only seems to work some of the time. Can anyone help?