Hi Steve,
Thank you for contacting Syncfusion support.
Query 1: when dynamically changing the selection mode as Range selection, calendar height increases
Based on the shared information, we have checked your reported issue. We would like to inform you that there are no separate views for the calendar Month view and the AgendaView. The Agnedaview will be disabled and the calendar will be rendered based on the given height request if you change the selection mode as a range selection. It's not an issue. It is an expected behavior of calendar.
Query 2: when I then set SelectionMode back to SingleSelection event details no longer appear
Currently, we are analyzing the mentioned issue. We will validate and update you the further details in two business days (January 21, 2021). We appreciate your patience until then.
Kindly revert us if you have any concern.
Regards,
Muniappan S