Hi sonny-1,
The behavior you describe is expected as outlined in the article Automatic track workouts on Apple Watch:
"Begin a Track workout
- Open the Workout app
on your Apple Watch. - Tap Outdoor Run.
If your Apple Watch detects that you’re at a track, you’re prompted to choose a lane.
3. Tap Choose Lane, use the plus or minus button to choose a lane, then tap Confirm.
4. If this is the first time you’ve performed a Track workout, choose a measurement unit (Miles or Meters), then tap Confirm.
To change the measurement unit later, open the Settings app , go to Workout > Units of Measure, then choose a unit below Track Workouts.
If you leave a track during your workout, your Apple Watch displays an alert telling you so. Similarly, if you arrive at a track during an Outdoor Run workout, you’ll be prompted to choose your lane." (emphasis added)
You may provide feedback based on your use of the Apple Watch app via site Feedback - Watch.
Regards.