On some Linux distributions, when using USB TMC (Test & Measurement Class)Instruments, they may not be accessible by a user other than 'root' if the
class of the instrument is defined at the interface level. If this is the case, access may be granted by using the "AddUsbRawPermissions.sh" script.
Try using that script to see if you can get the device to show up.
man 7 udev
#1: add a group for the access to the device
#2: add a udev rule that sets proper permissions on the devices
#3: properly package this, so no manual intervention (eg. hacks like having to call some scripts manually) is required.
More likely the problem is that Linux now has a native usbtmc driver "/sbin/modinfo usbtmc". I'd bet that the native driver is claiming the device since NI-VISA normally only picks up unclaimed devices.
Why not just using these mainline drivers directly ?