Hi,
I enabled both features resourceTimeRangesFeature and calendarHighlightFeature. When an event is dragged, the calendar is highlighted but the description which is defined in the CalendarInterval is displayed twice. This happens only if the resourceTimeRangesFeature is enabled, even without any resourceTime data.
In order to reproduce, just enable resourceTimeRangesFeature the in your online example provided in the docu https://bryntum.com/docs/scheduler-pro/api/SchedulerPro/feature/CalendarHighlight
Cheers,
Philipp