Walking workout recorded but not showing on exercise ring!!

Every day this month, I've been recording a 2.5km outdoor walk, and that has been showing on my exercise ring, along with 30 mins on the exercise bike - i.e. total of 65 mins exercise.

Today, I've just been on exactly the same walk, the watch, and my phone app, are both showing the recorded walk with the same distance, heart rate, etc., and yet the green exercise ring has stayed at 5 mins (just from usual home-based up and down stairs, etc).

I can't work out what's different... apart from the fact that I've just updated my iPhone? I've hard reset my watch, turned both on and off, updated the watch.... any suggestions? It doesn't need re-calibrating.

Just to stress again- the watch is showing the recorded workout with the raised heart beat etc and the green exercise ring is just above it showing that nothing has been done today?!

Very frustrating!!