Any policy will work as long as the parameters are met. For example, if you use Fixed Reorder and have a Reorder Point of 10, but have 100 on Hand, it won't make a suggestion. Either Order or Lot-for-Lot should work if the Quantity on Hand is Zero.
It may be a version issue. In older versions, the "Apply Usage Link" toggle needed to be On for it to pick up the demand. This is no longer the case in BC Cloud.