Thanks wcs2228 for your thoughts and explanation. I tried a lot of things yesterday… finally I got it to work
I got it working with the following method:
Connect a device to the camping WiFi.
Made a screenshot of the assigned IP, DNS, Gateway.
Disconnected the camping WiFi and clicked “forget Network”
Then I connected to the admin panel of my Beryl.
I searched for the WiFi network in my repeater setttings
Clicked on the settings wheel and manually added all the details.
After reboot my phone and Beryl I see the portal on the first device I connect to my Beryl WiFi.
All the other devices are connected to the internet now.