Kobo Browser not reading Calibre server

Hi,

I have my calibre-server running without problems and I can access it with firefox from other computers or Android tablets. However, when I try to connect with the Kobo browser, it gets stuck on the progress bar.
Trying the mobile version of the server does not work either: nothing happens.

I am certain that Kobo is the culprit here, but is there a solution for the problem?

My calibre version is 3.14

(sorry, I looked for duplicate threads, could not find them. But improbable that I am the only one with this problem)

Paai