Do not include the ‘and(“startDate”)‘ part in your criteria.
Instead of :
query.addCriteria(Criteria.where("startDate").gte(startDate).and("startDate").lt(endDate));
You should use:
query.addCriteria(Criteria.where("startDate").gte(startDate).lt(endDate));
When you include the ‘and(“startDate”)’ part, Mongo see’s it as two different entries on the same property.