Seems odd it mentioned USB at all since the connection is by wifi from the wifi extender on the controller.
Can you 'see' and connect to the network when you tun the extender on?
There won't have been any updates for several months but you might check by connecting it to phantom assistant on your computer.

I wouldn't be surprised if the incremental changes to smartphone firmware and such eventually cause problems when the Vison app is barely supported anymore.  You could keep things working if you had an older phone/tablet never updated.