Unable to upgrade Varia RTL515 to 3.36 firmware - Garmin Express always shows "There was an error installing the update"

Tried multiple times. Removed and re-added Varia RTL515 to Garmin Express.

Varia RTL515 is currently on 3.34 firmware.

Garmin Express shows there are 2 updates for the unit.

It always results in "There was an error installing the update" without any additional logging or messages. Tried removing and re-adding the Varia device multiple times, rebooted computer, results in same error.

Any solutions?