SD-based video displaying differently in two projects

I am getting two display results from the same clip used in two projects that have the same project settings. This is similar to a topic I posted in December but has a different outcome. The clip is a deinterlaced video output in Cineform AVI by an external program.

One project is from about 18 months ago that I created with Resolve 15. The project is setup for 640 x 480 resolution with 59.94 fps and square pixels. Image Scaling is set for "Scale entire image to fit." The image displays with the proper ratio in the viewer with Resolve 16.

The second project is a test project I created today in Resolve 16 using the same clip and project settings. The image in the viewer is considerably different. The image is shrunk vertically and black bars added on the top and bottom. I ran through the other input scaling options. "Stretch frame to all corners" restored the image to its proper proportions. When I tried this setting to the first project, the image shrank from the sides. Two different responses with the same clip.

Its odd that I have to use different input scaling for the two, supposedly identical projects. Any idea why this is happening?

Thanks,
Steve