Imported Intervals‘ training session can not use and show Stryd's power data in Garmin FR 965

It could only use and show the power data of the Garmin watch itself. Thus at the completion of the session, the achievement score is always 0% if power is the targeted index of the session.

Can you point me at an example?

Dear David, I just found time to do a test this morning so that I could take photos to explain the problem.
The Styd sensor was set for speed and distance always.

In the Run Settings, the source of Running Power was set to be Accessory Only.

Then I did an imported running session from Intervals. There was no power data on the default screen:
but there was power data (from the Stryd) on other screens:

Then I switched the source of Running Power to Smart Mode:

and power from the wrist power of my FR965 itself was shown on the default screen:

I compared this power data with the Stryd power paired with another watch (Polar VV2) and confirmed that the power shown on the FR965 was the wrist power.
I stopped the session and the execution score was only 16%:
It would be 0% if the power source had not been switched to Smart Mode.
The imported session results in Intervals showed the power of the Stryd anyway:

I am not sure can do anything about that, unfortunately. The Garmin API accepts steps with targets like POWER_LAP or POWER_3S with a range but nothing more than that. So showing Stryd power or not on that default screen isn’t something under control as far as I can tell.