Hi Jpittj,
Thanks for coming to Apple Support Communities for help today.
Make sure you are following all steps found here to pause and resume the run: Run with your Apple Watch.
"How to pause your run
To pause your run, press both the Digital Crown and the side button at the same time. To resume, press both buttons again.
You can also set indoor and outdoor running workouts to automatically pause when you stop moving.
- On your Apple Watch, open the Settings app, then tap Workout > Auto-Pause > Auto-Pause.
- On your iPhone, open the Watch app, tap the My Watch tab, then tap Workout > Auto-Pause > Auto-Pause. "
If the issue continues, make sure both devices are updated completely to rule out this issue being related to an outdated version of watchOS or iOS. Here's how:
- Update your iPhone or iPad
- Update your Apple Watch
Then if the issue continues after updating, contact Apple Support for a deeper dive.
Have a fantastic day!