Cerbo GX Lenovo tab M8 connection problems

When I try to connect our Cerbo GX MK2 to a Lenovo M8 tablet I always get the the error message 404 page not found after selecting the cerbo in the set up Assistent.

I see the cerbo in the set up assistant list, if inhale connected it to the internet via my mobile phone hot spot, otherwise the list is empty.

the tablet is now completely frozen. A reset ends up with the same error message 404, shortly the message „cannot connect to Cerbo, reload“ is shown.

does the cerbo itself have to have an internet connection in this initial set up process or is it sufficient if the android tablet is connected to the internet?