I have the same problem and finally gave up after many attempts... Perhaps my TechniSat Digit Isio S2 is also too old, it doesn't receive or have any updates from TechniSat. I have been forced to lay LAN cables...
Unfortunately, your receiver is not on the compatibility list, so it is not compatible.
You can access this list here: https://www.technisat.com/de_CH/TELTRONIC-ISIO-USB-Dualband-WLAN-Adapter/352-8773-22456/?article=0005/3633