Are the boards recognised by your PC?
I have another guess, but not sure it will solve the problem.
Those boards need to have the WIFININA firmware updated to the latest version in order to operate properly. Upload the firmware checker sketch to your boards to see if they have the latest version. If not, upload the updater sketch e run the updater app.
You can get more info on this process at https://www.arduino.cc/en/Tutorial/WiFiNINA-FirmwareUpdater