I see the update button now ?. Will be a different software build. Mib2 standard and Mib2 high and generations. Mib2 high were all fitted to the pre FL
Ateca Cupra sold in the UK. They feature the maps held in the unit on internal storage, the standard unit on a map card. They also have the Jukebox where if you keep stabbing the media button the Jukebox comes up or you can access it via other means. That's spare solid state memory where audio files can be moved to for playing. The high uses Here Maps cartography, the standard TomTom. The high units could be specified at a cost, +£600 or so for the early Atecas, most didn't bother, Seat changed how they sold the top end products and reserved them only for Cupras and bundled the options differently withdrawing the ability to specify top of the range products (I bought mine with all the trimmings in 2016 which subsequently you could only buy on the Cupra Atecas).
The high mib2 infotainment system called a Seat Plus is a better specified product although the standard does the job. Faster processor, drag and drop to change routes and better roundabout displays of next turn. Mib2 standard navigation can lag, whilst mib2 high doesn't. Finer point you won't notice if not using the built in navigation.
That will explain why you aren't seeing that button different software and different hardware. On my high unit I've always seen what is available locally and pick it off the list. Attached is the infotainment unit manual at the time. It should cover the differences in the two types of units with a note. Seat documentation isn't always brilliant. There are different firmware builds each year, fixing issues but I suspect that button isn't designed to be in the high unit so was never in the spec.
I will have a look later today for that "update" button but I don't reckon you need it, it's automatic (my unit is on 2018 firmware, 1338, so will be similar). The attached manual covers the other Dab functions of finding similar stations automatically (On / Off), traffic reports etc. Likely once only customisation but do alter the way Dab works.