May 2021 Map Update

[Berlin]

Hey all.

Have a 2017 S60 Inscription Platinum. Have updated the maps via the USB (+ download from Volvo site) a couple of times over the years-- it's always worked a treat. However, I am trying to update my maps with the May 2020 release just posted on the site (December 2019 was the old version). I am able to download the ~16GB file to the empty 32GB flash drive (FAT32, of course) no problem. But when I plug it into the car, "Map data already installed" displays on the screen and the only option is to exit. I've confirmed that the map version in the car is different than the one I downloaded, but no dice. I deleted the update from the flash drive and started over, but I got the same result. I emailed the customer service center-- who said that they don't have anything to do with the map updates. Local dealer wants $195 for a diagnostic.

Wondering if anyone has encountered the same and has a fix!! Thanks in advance.