Firmware not updating

Hi there i am on iOS 17.0.2 and the latest ZC 3.51.1

I have just got a new zwift hub - I try to update the firmware (the ZC says my current firmware is 0.0.0 hardware version 1)

I left it updating for 13 hours only for my phone to say that there is a firther 1438 min

I have tried multiple times and I cannot update the firmware

The hub and phone are next the the router - there is nothing else on the WiFi or Bluetooth (the hub shows as connected to the phone via Bluetooth)

At a complete loss - and very frustrated , spent all yesterday afternoon on this to no avail