I've had an HR spike and Garmin autodetected new max HR as 248. I have used Garmin Connect app to set it back to 176. However, all new rides after saving show Time in Zone calculated based on Max HR of 248 - both in the Edge, as well as in Garmin connect app. I've checked Max HR after syncing the unit after a few rides and it is showing as 176 in the app.
Has anyone experience anything like this?
Any ideas how to fix Time in Zone graph?