Unfortunately, many devices are made without registering as a Vendor with the corresponding standards body, and use generic USB chips for interfacing with a computer (roughly similar to using a network interface card with a random MAC address and PCI ID, and thus poorly identifiable device specifics needed to automatically load some certain driver). Often they also lack a unique serial number field, so monitoring several devices is problematic.
One frequent case is with devices identifying as "Fry’s Electronics" and/or "MEC0003", if those data are served at all, or plain "0001/0000" in ID field. In some cases they are accompanied by "UPSmart" software with a "MEGA(USB)" connection option that works for Windows users.
Your best bet is to search for community discussions of issues on NUT GitHub
at https://github.com/networkupstools/nut/issues?q=is%3Aissue and try options
there. Devices with these chips were known to connect with drivers for such
unrelated protocols as Megatec Q* (different sub-drivers, often fabula
or
hunnox
), ATCL, or USB-HID.