That means it lost preboot mode and entered Mass Storage Mode. Most units only stay in preboot for a limited time so you need to do this stuff very quickly. Also if you release the pressure on the screen even a fraction too soon it will drop out too, hold it until the flash finishes if you can and at least until 'Software Loading' or such appears.

There is another way to enter a type of preboot mode where the unit will maintain the state indefinitely but i'm unsure if it will work with these very new models. Let's try though: Simply go to the first screen 'SW Ver' of hidden menu behind the battery symbol, no need to press any further or hold the screen, do 1 to 3 as in Post#8 above and then just connect the usb and see if the device details show next to 'USB Device' in Updater's GUI, if it shows then press 'OK' or hit enter key. All that can be done quite leisurely. If that doesn't work, then try this:

Do 1 to 3 then proceed like this for 4: Turn on the unit, immediately the 'Garmin' logo appears press and hold the upper LH corner of the screen firmly [easier to use your left thumb for that rather than a finger btw], then immediately plug in the usb cable to the unit. Then do 5 to 7 as above. Everything must be done very quickly with that method too.

PS: You've confirmed your HWID is 1948 and SW Version [firmware version] is V7.80 like i asked, did the SW Version override to 781 and named the RGN properly too, didn't you?