You can update this firmware and maps as explained in the post above made 09/03/2019.Found one on eBay for $38.50 and it's dated 2016, but it's still fairly accurate for my needs.
Can't post the link, but search for "Mercedes Benz Navigation SD Card CLA CLS GLA SLC GARMIN Map Pilot A2189066002" and the price is still the same.
Arrived in a few days. Takes a few minutes to load up.
I just saw this post. How do I know what to purchase/look for on Amazon or eBay? My 2020 GLA has “audio 20 Garmin nav prewiring.”