4watts So it does look like your two exports one from 17:00-18:00 and another 18:00-19:00 messed things up a bit.
Your 18:00 got set up at 17:55 but your end export from your 17:00 export kicked in at 17:58.
If you have adjacent export schedules like this, it may be best to leave a 5 min gap or so, to be sure.
Due to the many schedules that people have set up, we simply cannot check or run schedules every minute, during busy times, they may not even all be kicked off within 60 seconds, especially when you consider we have retry policies in place too.
Hope that helps!