Watch Workout data not updating green ring on Activity

I have a brand new Apple Watch series 3, updated to latest software and an iPhone 11, also updated to latest software.

Wore watch for my first workout this evening. Did a 35 min row on an indoor rower, heart rate between 130-155 for most of the row. Used the workout app on the watch, chose indoor row, ended the row on the app when finished. The calories burnt appeared straight away on the Activity app, the pink ring filled up nicely, the green ring didn’t budge, 0/30.

I can see the workout on my iPhone on the Activity app, the row appears under workouts, shows the time as being 35 mins and 42 seconds...just above that the Exercise section states 0/30 minutes. It’s like the workout app isn’t communicating with the activity app but only on time, as calories burnt updated fine.

I’ve tried hard reset on both devices, checking all the settings are as they should be. Googled and none of the solutions work. Wtf.

What’s the point in paying to have the watch if it doesn’t do what it’s supposed to do? Any suggestions for a fix?