Garmin Express on Mac: During the update process, the device is connected and syncs. If there is an update (such as maps for example) the update is downloaded, but then at the point where the update ca be installed, Express asks for the device to be disconnected and reconnected - the device is already connected at this point, there is little logic to disconnecting and reconnecting it.
Garmin Express can very rarely find the device again after you reconnect it so you end up giving up on the update.
The enhancement request would be a potentially more beneficial approach, which would be to maintain that existing connection - you have the connection already in order to sync and realise there is an update - just maintain that working connection until 'after' the update is installed, it would make updating the devices so much easier and way more successful.
After the update is installed, you can then disconnect/reconnect at that point, and it won't matter as much that Garmin can't re-establish connections.
Cheers