Garmin Express on Windows 10 recently stopped seeing my Varia RTL510. Unable to update the Varia software.

Garmin Express has stopped seeing my RTL510. The RTL was successfully added to GE about a year ago. Recently notification on GE showed that 3 updates were available for the RTL. When I tried to run the update, GE reported being Unable to Connect. I have tried multiple cables, all available USB ports, repairing with my Garmin 25, with RTL both on & off. I removed the prior RTL from Express and tried adding it again. I have tried uninstalling and reinstalling GE. I was able to add my Garmin 25 to Express without any drama. All attempts to add the RTL failed with no device found. The RTL is paired to my Garmin 25 and still appears to work as normal as both light and radar. Help!