Connecting Kobo ClaraHD to intranet

I need to be able to connect my ClaraHD to intranet (rather than internet).
Normally, when I try to do it, I get the message:
"Unable to join ...."

There is a workround which involves temporarily connecting it to the smartpone hotspot with with the same SSID and Password as desired network to "fool" Kobo.
It kind of works but is not reliable :(

I tried this:
https://www.mobileread.com/forums/sh...196&styleid=17
but it didn't make any difference...:blink:

There is also a suggestion of forcing wi-fi on using developer settings?
https://www.mobileread.com/forums/sh...d.php?t=314955
but my searches so far didn't come up with any advice on how to do it?

so... :help: please.
Has anybody got any suggestions?