Unable to change scale/pan of Effect Source in FCPX

I created a Final Cut Effect in Motion 5 that shows the cropped effect source next to a drop zone like below. I am using it to show a video clip (effect source) next to a photo (drop zone). The effect works well except for one problem. I am unable to adjust the scale and pan of the effect source. I've published those settings in Motion along with the scale and pan of the drop zone. The settings work for the drop zone but have no effect on the effect source in FCPX (they do work in Motion, however).

I'm new to Motion and FCPX (and video editing in general) so I'm guessing I'm overlooking something simple, but I can't see anything obvious that I've missed.

Does anyone have any suggestions for me to try and fix this?

Thanks,
-Dave

That scales the entire screen (drop zone, effect source, borders, etc), not just the effect source. I want to "zoom in" on the video clip, not scale the whole effect.