After creating a new world, moving away from spawn area so that it is no longer loaded; when the view distance is increased by any margin, a section of chunks will no longer load.  Decreasing view distance does not cause this  The size of the area seems to correspond with either the distance increased, or the final distance.  Dying, or reloading the world reloads those chunks, but neither F3+a or F3+t seems to make a difference.