Export of 4K H.265 Video looks like slide show
I just finished editing a project that was shot in 4K H.265 on a DJI Mavic Air 2. The video edited just fine in Premiere Pro CC, and the entire sequence plays perfectly in the Program window.
However, when I export the video, each clip only shows a still frame. The audio and video fades work as I designed them, but there is no video - only still images (probably the first frame from each clip).
(If it matters, I am editing on a Win 10 laptop (Intel i7-7700, 16 GB RAM, and an Nvidia GTX 1050 GPU.)
Help please!