Hello JT_788,
There are a few steps you can try to resolve this issue.
First, make sure both the Apple Watch and its companion iPhone are up-to-date. If not, make a backup of the iPhone and update the software for each device. The update process can frequently address unexpected software behavior. Here are some pages to help with these updates:
If they are on the current software and you still have the issue, try powering off and restarting both devices. Often this simple step will refresh the apps and software on the device to solve numerous problems you may encounter.
Another steps to try, would be to calibrate your Apple Watch. This can help to improve the accuracy of your distance, pace, and calorie measurements. Calibrating can also help your Apple Watch learn your fitness level and stride, which improves accuracy when GPS is unavailable. Here's a guide to help: Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support.
Kind regards!