<p>From 31 October 2024, BT Cloud has <a href="https://www.bt.com/help/broadband/bt-cloud/getting-set-up/download-or-access-files/how-do-i-download-files--folders-and-devices-from-bt-cloud-">closed</a> and all data will soon be deleted.</p>
What devices are there between your box and phone? Powerline adapters? WiFi repeaters? First step would be to reboot everything - including the box, phone, router, and anything extending the network.
