4K to 1080p Distortion Interpolation?

On a 1080p timeline I have a 4K video. Using Motion I am scaling to zoom out from area in zoom and Position to adjust the frame to keep the pixels on the program area.

What I see however is not flat. There is a severe dolly-zoom effect happening here and something I had not seen in 13.0.

It looks like the Lens Distortion effect (but that is not applied to the source or timeline clip) and I cannot find out how to adjust or turn off this distortion added by clip interpretation/interpolation. Linear keyframe does help a little I think....slightly.

Any ideas?

Thanks!