Hi Cormac,
The guidance for factory defaulting your AnywhereUSB 2 Plus can be found here:
https://www.digi.com/resources/documentation/digidocs/90002383/default.htm#os/system-reset-to-factory-defaults-t.htm
Where guidance is concerned, on the AnywhereUSB 2 Plus we'd recommend using a Static IP address, Subnet Mask, and Default Gateway addresses, as well as configuring a primary and secondary DNS server address.
On the AnywhereUSB Manager side, you can configure the Static IP address of the AnywhereUSB 2 Plus under Configure --> Known Hubs, so that you can de-select the Autofind Hubs option under File --> Preferences.
Hopefully this guidance gets you up and running, but if you feel the need to pursue an RA Request so you'll have a working product, please email tech.support@digi.com and provide the Serial Number of the device you're having issues with, since the forum isn't really made for troubleshooting of an ongoing issue such as need of repair.