Hi kericson62,
The Exercise ring moves when it detects your activity level to be at or above that of a brisk walk. If you're walking at a slower pace or doing activities that don't elevate your heart rate, it may not be counted by the Exercise ring.
"Close your Exercise ring by completing at least 30 minutes of activity at or above a brisk walk.
The Exercise ring shows how many minutes of brisk activity you’ve completed, whether you’re just moving at a fast pace or doing a specific workout in the Workout app. All at once or a little at a time, you can earn Exercise minutes however it works for you"
Another option is to double check your fit. The Apple Watch should be snug, but not overly tight against the wrist for best results. You can see additional tips on making sure your Apple Watch is measuring accurately in the article below.
Cheers!