Was riding today on my Specialized Turbo Vado SL 5.0 and Garmin 840 with newly updated 21.19 firmware. A couple of unusual things happened.
Once, when I was mid-ride, a message came on the 840 screen that said the battery was low on my bike. The actual level was 89% on the Garmin data screen. Also, on the bike it was fine. I pressed X and it went away.