When only 'one' event is there in scheduler, the content is partially viewable and we have to scroll down to view that only one event detail. We have specified, HeightSpec="Max" Height="275"
HeightSpec="Max" means the height will never be more than Height value (in pixels).
You can try HeightSpec="Full".
You can also set the initial scrollbar position using ScrollPositionHour property.
The above answer applies to the Calendar:
http://www.daypilot.org/calendar.html
For the Scheduler, use HeightSpec="Auto".
See also:
http://www.daypilot.org/scheduler-height-vertical-scrollbar.html