DNS servers are responsible for translating domain names into IP addresses, which are used to access websites. If the phone has limited internet connectivity, it might be because the DNS servers are not working properly or are blocked by the network. The technician should check the DNS settings on the phone and try to use a different DNS server, such as Google DNS (8.8.8.8 or 8.8.4.4) or Cloudflare DNS (1.1.1.1 or 1.0.0.1).