Uno WiFi Rev2 WiFi port bricked by Firmware updater

IDE: Arduino 1.8.8 running on network booted Raspberry Pi 3 B+.

Update of WiFinina firmware from 1.0.0 (as supplied) to 1.2.1.

Running CheckFirmwareVersion returned V1.0.0.

Loaded "FirmwareUpdater" sketch and ran the "WiFi101 / WiFiNINA Firmware updater" plugin.

Selected "Arduino Uno WiFi Rev2(/dev/ttyACM0)" and "NINA firmware(1.2.1)(Arduino Uno WiFi Rev2)"

"Test Connection" reports that the programmer is working.

"Update Firmware" erases the target and programs 880640 bytes. This takes about two minutes. The plugin then reports "Error validating flashed firmware".

The console reports;
java.lang.Exception: Error validating flashed firmware.
at cc.arduino.plugins.wifi101.flashers.java.Ninaflasher.updateFirmware(NinaFlasher.java:106)
at cc.arduino.plugins.wifi101.UpdaterImpl$2.run(Updater.Impl.java:196)

"CheckFirmwareVersion" now reports "Communication with WiFi module failed" although reloading the updater sketch and "Test Connection" still reports "Programmer is working"

I've re-run the process a couple of times but to no avail.

WiFi processor effectively bricked!!!

Start with the FirmwareUpdater sketch and the WiFi101/WiFiNINA firmware updater flow described in the report. Inspect NinaFlasher.java around line 106 and reproduce the update with an Arduino Uno WiFi Rev2. Done means the firmware update completes without the validation error and CheckFirmwareVersion can communicate with the WiFi module afterward.

Written by the indexing model from the issue text.