I Was able to get heart rate syncing when doing an outdoor activity
In strava there is an option to allow data from watches to be synced. See image

Nothing support said the below statement which i think is fair.
To clarify, Strava currently only supports syncing activities that use GPS tracking, such as running, jogging, cycling, and other outdoor workouts. This means that while distance, time, and GPS data will sync successfully, activities performed indoors (like treadmill runs or gym workouts) unfortunately won’t transfer heart rate or calorie data to Strava.
You MUST START THE ACTIVITY ON THE WATCH TO GET HR DATA. I RECCOMEND THE FOLLOWING
1.START WORKOUT ON WATCH
- START WORKOUT ON STRAVA
SAVE STRAVA WORKOUT FIRST AT END OF ACTIVITY FIRST
STOP WORKOUT ON WATCH TO ALLOW IT TO SAVETO STRAVA
IF GPS ON WATCH LOOKS GOOD AND SYNCS TO STRAVA. THEN DELETE THE STRAVA workout and just keep the watch one with HR data