If you install Stryd Zones to get the power data field on your watch, you can modify the data you see in that screen.
Per default, the power data field shows real-time power. You can change that to be 3s, 10s, 30s, lap or overall average.
If you running in hilly terrain, or change your pace frequently in a run, real-time power likely will work best for you since longer averages require more time for power to update on the watch.
However, some runners prefer to have a longer average since power can fluctuate a bit from second to second. To change the data field settings, go into Garmin Express or Garmin Connect Mobile. This video is for Garmin Connect Mobile on an Android phone (the iOS version is slightly different).
After making the change, sync your watch again to update the setting on the watch.
If you have additional questions, contact firstname.lastname@example.org.