Buffer time in NeetoCal adds a gap before or after your meetings so you are not booked back to back. Once a buffer is set, NeetoCal blocks that padding time around each meeting and hides those slots from your booking page.
Set a before buffer to prepare for a call and an after buffer to write notes or take a break. With a 15-minute before buffer, a 10 AM meeting also blocks 9:45 to 10 AM, and NeetoCal keeps room for the next meeting's buffer too. By default, buffers also apply to events on your connected calendars, and you can turn that off. Add buffer time to each scheduling link from its Where tab.