Backups running slow

Server 2016 Hyper-V host running Backup exec 21, RAID 10.

About 2 weeks ago, backup to disk has been running verrry slow.  Backing up the server itself to disk is currently running at under 200mb/min.  It used to run around 1300mb/min.  Backup to tape is also running slower than usual but I usually backup to disk and then backup the backup to disk to tape so I have 2 copies and guessing backing up a backup to disk to tape is faster than backing up a live server to tape directly. 

Hardware diagnostics show that the hardware is ok.

VSS writers show ok.

No active errors.  Just running really slow.