I was having a problem with my iPad Mini in that links to web sites that should load from other apps like email do not load. The problem also affects the ability to load hotel captive portal pages, which means I couldn’t connect this iPad to the Internet in some hotels. The problem appears to be NextDNS, which while I had disabled it in the app the DNS settings were still pointing to it. After I changed the DNS setting to automatic I could open the captive portal page.