Antivirus won't Scan Network Drive (NAS)

I’m unable to get CAV to scan my network drives that are mapped to my PC. Windows 7
However when I right click on a network drive, then on scan with CAV, it says the scan is finished within a second. This cannot be correct.
Can someone help me please?

Which version of CAV are you using?

Comodo Internet Security
Product Version: 6.2.285401.2860

have you scanned the drive before? CIS uses caching so if you scanned it before and the files havent changed the scan speed will be almost instant.

No, the network drive has not been scanned before.
Not sure why it won’t scan the drive

im not sure either. it should be working, maybe someone else has some ideas