The configuration for older versions of the box needs a firmware rename (my box is labeled 93000 Rev B8A2 Lot 1905):

The system tries to load a specific firmware name from /lib/firmware:
dvb-usb: found a 'Hauppauge WinTV-NOVA-T usb2' in cold state, will try to load a firmware
dvb-usb: downloading firmware from file 'dvb-usb-nova-t-usb2-02.fw'

This version can be found on the internet
(Index of /Temp/nova-t) BUT scan/tuning won't work e.g. with Kaffeine.

Instead, download the version 01 from the website above and rename it to 'dvb-usb-nova-t-usb2-02.fw'