Have you configured MPIO on the Windows Server for your tape drive? Veeam's gonna see whatever Windows does, and if Windows sees 2 changes and drives, so will Veeam.
Figure out the MPIO/Failover stuff for your tape drive (check the documentation) and it should be fine. Else, just remove one of the FC connections for now and rescan the hardware in windows. Once you've got your multipathing set up correctly, just rescan again and Veeam/Windows will see it fine.
I wish I could give you more information, but it's going to depend heavily on what you've got for hardware.https://support.hpe.com/hpsc/doc/public ... -c04325872
I found this on a DDG search quick for HP Autoloader MPIO. Maybe it can help?