Exchange 2010 Transaction logs not deleting

BE2012 backing up two member DAG properly (circular logging off.) On job completion VSS on MB server generates log entry saying "VSS copy complete, transaction logs not deleted." VSS copy means logs not deleted. VSS full means logs should delete. I have other sample databases on each DAG server same thing happens. How do I get the trans logs to delete?  I see a way to force VSS copy in the freeze script but not force a full. VSS writer status shows no problems, DAG healthy. Properties of all databases show no Last Full Backup time and date either. Help!