I've got several reports that the calories counter stopped working (value remains at 0) as of FR245 firmware version 5.20 (and I see it also mentioned in the release thread https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-245-series/243376/forerunner-245-music-sw-5-20---live-to-100 ) .
So most likely this is a firmware issue, can you direct the device team to this issue? Thanks.
