Reminders late notification

Hello,

I'd like to ask you, I know that reminders on OS X El Capitan have 5 minute, 1 hour, tommorow option of snooze.

I had 2 reminds that notificated to me, so I clicked on 5 minutes snooze on both. One remind showed after 5 minute and the second remind showed after 15 minutes? Does anyone have same problem?

Maybe I saw that one remind showed me 15 minute option? Is that possible? Thank you