Some newer Garmin watches will try and give you an estimated wrist-based power. This estimated wrist-based power is Garmin's Native Power Value. Wrist-based power estimates are ok, but Stryd Power is much more accurate and responsive.
In order to properly collect Stryd metrics and view Stryd Power during your run, you will need to disable the Garmin wrist-based power estimate.
Here is how to disable Garmin's Native run power (wrist-based power) value recording so it is not recorded to the FIT file for the Stryd Zones data field.
Press and hold the "UP" button on your Garmin watch to access Settings.
Scroll down and select "Activities and Apps".
Please note that you will need to deactivate Garmin's Native run power for any activity mode that you want to use Stryd Zones Data Fields with. Common modes to edit are Run, Treadmill, Track, Indoor Run, Trail, etc.
Select "Run Settings".
Or Treadmill Settings, Track Settings, Indoor run Settings, Trail Settings, etc.
Scroll down and select Running Power.
Turn this feature off.
If you already use Stryd, there is no extra benefit in using Garmin Native Run power. In fact, data will not be reported correctly in the fit file if you try and use both Garmin Power and Stryd Zones Data Fields at the same time.