Cycling workout recorded but not registering as exercise - Apple Watch 5 iphone 12 pro

Hi -- All of my other workouts register as Exercise, but for some reason not outdoor cycling. I only cycle occasionally, mostly run, use rower and strength training. All of those workouts register as time exercising, but not cycling. In the workout info, it shows how long I cycled, the distance, heart rate, and the map, so I know GPS is working, as well as all of the other functions. But yesterday, for example, I cycled outdoors for an hour and 10 minutes, and the app showed that I had exercised for 5 minutes.

Suggestions?

Thanks,

William