Brand new Edge 850 device and Strava Segment Explore widget seemed to work out of the box. Synced with Garmin Express and updated to the latest firmware and now the Segment Explore widget has stopped working and tells me a Strava subscription is required. I have said subscription and Segment Explore works fine on my Edge 530 still.
As per the similar issue people found with the 1040 I've tried disconnecting Strava and Garmin and reconnecting. I've tried disconnecting from the connect app and bluetooth, and reconnecting. Neither of which have worked.