I honestly don't know why Roku bothers having numbered codes when they don't tell you what they mean... welcome to the Roku world.
I can't offer much advice as the usual remedy is to use an alternate network. Are you sure your phone can't act as a hotspot?
As for USB updating, that's only for actual Roku TVs. Most of the devices that use a USB power adapter don't even have a real USB port (it's just for power) and even those that do don't allow for updating via the USB port.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.