Why doesn't Garmin Connect share SpO2 (Pulse Ox) data with Apple Health app?
Please add your vote here: https://forums.garmin.com/apps-software/mobile-apps-web/f/garmin-connect-mobile-ios/254977/request-for-spo2-vo2-max-and-respiration-data-to-be-shared-to-apple-health-app
Did you ask the same question of Apple Health?
Why would they do that? Apple Health is perfectly capable of receiving the data and sharing to other apps, and does so with my other Pulse Ox devices. This is a Garmin Connect issue.