iPad cannot get on wifi Error Opening Page

Hi! Suddenly today my iPad cannot get on my home wifi - it hasn’t left home for a long time, it was connected to the wifi well yesterday.

when I try to join the wifi it shows:

Error Opening Page: Hotspot login cannot open the page because too many redirects occurred.

the broadband is Vodafone

most questions with this same/similar error message is about safari, my safari is fine - my ipad can connect to my iPhone’s hotspot and open any pages on safari. Though I followed the suggestions to fix safari but apparently it doesn’t work.

could someone please shed some lights? What should I do to connect my iPad to the wifi?

Thank you for you help in advance!