Why doesn’t health app import garmin connect heart rate data

The health app is set to accept health data from Garmin Connect and heart rate is on, but the data collected is only basic activity type, time and distance. No heart rate or other data is collected therefore health app mis-calculates VO2max and other health measures. Apple Watch seems to stop taking heart rate readings during my activity (using a heart rate monitor connected to my Garmin 1030 which is not collected by health app)