Montana 700i or Connect doesn't recognize microSD card in removable storage

 Couldn't update TopoActive map from 2020.10 to 2020.20 on new Montana 700i.  Errored out on install.  Chat with Garmin support indicated that the 2020.20 update was bigger than the available memory left on the device, and that I should buy a memory card and insert to allow the update to have enough space.  

Bought a 32GB class 10 Sandisk card.  Installed it.  Was formatted to FAT32 when inserted, didn't have to do that.  

The my maps window on Express has a (1) after City Navigator and Points of Interest and a (0) after Topographical maps in the My Maps tab.  The finder on my Mac OS laptop shows the card mounted as a volume as well as the Montana 700i internal memory (both as mass storage).  But the Removable Storage tab do NOT show anything.  and attempting to download the topoactvice update still errors out.  

What to try next?  Very frustrated.