I encountered same problem. The rows in msdb.dbo.backupmediafamily with
physical_device_name in format '{76F.........}9} results of periodic backups databases by VMReplicator . in error log of instance you may find :
Database backed up: Database .... device information:(FILE=1,TYPE=VIRTUAL_DEVICE:{'{76F.......}9'}) .Solution probably is ignore rows with device_type=7 in msdb.dbo.backupmediafamily when you
look for "last" local backup.