Limits on size of usb drive attached to EX2?

Is there any reason to believe that attaching a 12TB USB drive to my EX2 (not ultra) can’t be used as a full function shared drive (formatted NTFS).

I’m using this drive for backups of multiple windows systems. I’m finding that when my windows systems try to write to the 12TB drive, they successfully take full backups but the backups fail when they take incremental ones.

I found that when I move the 12TB backup drive and attach the same device to another host system (it happens to be a raspberry pi, sharing the drive using samba) and direct the backups to this new host, the backups to the 12TB usb drive run fine, leading me to believe there is a software limitation in the EX2.

Is there a limit on the size or type of usb drive that can be attached to the EX2?