Well a letter of complaint yesterday to Garmin got a standard scripted response of update you Garmin express and make sure your sd card is formatted.Yet strangely the install of the US maps which didn't work yesterday started to install today!
I used the contact link here https://support.garmin.com/en-GB/?topicTag=region_mapsgarminexpress
Oh and you can get 20% off some with code TOPOPRO19 unfortunately it doesn't look like the US map is included in the offer
https://buy.garmin.com/en-GB/GB/c60...EA, TOPO Maps Promo 2019 Hike Reminder, 12453
I used the contact link here https://support.garmin.com/en-GB/?topicTag=region_mapsgarminexpress
Oh and you can get 20% off some with code TOPOPRO19 unfortunately it doesn't look like the US map is included in the offer
https://buy.garmin.com/en-GB/GB/c60...EA, TOPO Maps Promo 2019 Hike Reminder, 12453