SupportAssist OS recovery in BIOS doesn't recognise either wifi or ethernet

Hi All

I've ordered a new SSD (nvm) for my XPS13 9310 laptop.  Before it arrives, I thought I'd check out the OS recovery in the BIOS.  It complained it couldn't access wifi and I should install a USB to Ethernet adaptor, so I ordered an Anker A8313 USB-C to ethernet which works in Windows without any drivers.

I still get the same message when I choose the SupportAssist OS recover option in BIOS.  I found a BIOS update and hoped that would fix it, but the problem persists.

I wonder if the BIOS option only supports a Dell USB->Ethernet adaptor?  It doesn't seem to support a Dell wifi module.

Am I doing something dumb?

I guess I might have to 'slum it' and download a Windows install image to a USB stick.

Cheers

Steve