Problem solved. I rendered a small portion of the video using a resolution of 1616 x 1080, and uploaded it to Vimeo. (For pictures, I prefer this resolution to 1920 x 1080, because the pictures were composed based on the aspect ratio used by the camera.) It’s playing properly both locally and on Vimeo. Thanks for the responses and suggestions. I never could have figured this out on my own.
Terry