Dell 9020 - Windows 10 with the latest Microsoft patches.
Installed Garmin express fine. Registered my Garmin 106sv Ultra and added it. Tried to download maps using a SC card. Once you select download it stayed at 0% downloading forever. Tried multiple times with clearing browser cache, running ccleaner, reboots in between. Nothing seem to resolve it. Once I launched download the CPU went to 100%.
The solution for me was turning off "Always keep Garmin Express running in background" and "automatically launch Garmin Express when a Garmin device is connected. Saw a similar thread that lead me to that. Then REBOOT the PC.
Then and only then did I see the download start and the transfer rate and hours left to complete the download.
Thought I would pass that along in case it helps someone else.