In the first image you can see my app at the top of the list, and Apple's Weather app widget. Both are showing the SF Symbol rendered correctly.
In the second image the inline widget chosen is Apple's Weather app. The SF Symbol is correctly shown.
In the third image my app's inline widget has been chosen, but the image is not rendered correctly; it's just a block.
Is there something I have to do to my image to have it rendered correctly?