Look in garmin folder if you have inside garmindevice.xml or maybe garmindevice.tmp if you have tmp just rename to .xml and webupdater will see device.
If this don't work then try this:
Flash in pre boot again with folder original and then use prepusb and set it like on picture and format
Then create empty folder Garmin and turn off/on device and you will hawe garmindevice.xml inside folder garmin and webupdater will see device.
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