After completing a treadmill run, selecting "Calibrate and Save" saves the updated distances and times as expected and can be viewed with the Garmin Connect iPhone application. However, when looking at 3rd party apps (ie Strava), those apps are being send the original, non-calibrated data.
Fenix 6 software version: 4.30 (48054d2)
Garmin Connect iPhone app version: 126.96.36.199
Hopefully I am submitting this in the correct place - not sure where to post. Thank you!