Bug in notifications? Battery level glitch? 21.18

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.