Hey there jeroldw502,
Thanks for reaching out to the Apple Support Communities. Just to confirm, does this issue occur when there is a period of inactivity during your workout? If so, you can disable the setting that reminds you to end your workout which can cause workouts to pause by going into Settings app on your Apple Watch, tap Workout, then go to End Workout Reminder.
Check out this link for more details: Get reminders to end your workout - Apple Support
Get reminders to end your workout
In watchOS 5 or later, when your Apple Watch senses that you're done working out, it taps you on the wrist and asks. Tap the notification to end or pause the workout, or dismiss the notification and keep working out. If you don’t respond to the notification or you dismiss it, your workout continues until you choose to end or pause.
How long it takes for your watch to notice that you've stopped varies by workout type.
To turn this setting on or off, open the Settings app on your Apple Watch, tap Workout, then go to End Workout Reminder.
Also during walks, be sure that your arms swing naturally, as the Activity app relies on arm motion and an accelerometer to track movement.
You can find this and more information about getting the most accurate measurement from your Apple Watch at this link here: Get the most accurate measurements using your Apple Watch - Apple Support
Keep us updated on the results.
Have a great day!