This just occurred to me...
There are a lot of complaints about the Exercise ring— specifically relating to Outdoor Walks. People have complained that they've walked a lot but have been credited with little exercise time, i.e. walking for an hour but getting only 30min of Green.
There could be software bug, but I chalk it up to Apple setting a standard based for a 'brisk' pace (whatever that is) to earn Green, and if you fall below that (apparently unknown) standard, you stop earning Green. This make prefect sense to me, but a lot of people don't seem to agree.
I'd like to see Apple have the option of a pacing beep toggle. Toggle On, and if you fall below what ever Apple decides is the minimum speed to earn Green, you get a warning tone and some beeps to establish a minimum qualifying pace. An option would be to quell it once you hit your stride. Slow down and you get the Beep. Or keep the Beep.
But the idea is for Apple to give you a clue as to the minimum pace to earn green. FB time!