If not, any alternative ways to sync them automatically?
I prefer the layout and cleaner UI on POLAR Flow when compare to Garmin Connect. But the Garmin watches works better for me overall.
Polar pull data from Strava?
You better look at Polar. This is a Garmin forum, so most people here know nothing about Polar. If you are lucky, perhaps someone familiar with Polar comments later, but you'll get the answer much faster when you ask at Polar (or at Strava).
just noticed there isn’t a Polar forum. Will see if the support there can answer my question.
welcome any input from other Garmin users as well.
[update] got a verification from Polar Twitter. They said the Strava <-> Polar Flow link is just one way, Polar flow feed data to Strava