Most frames render something like this:
[![good render][1]][1]

But some frames render with strange geometric artifacts, like this:
[![artifacts render][2]][2]

What could be causing it? Everything looks fine in the preview render. Problem frames include #2, #15, #18, #19, #20, #23, #24, #29, #48, #52, and more.

[Blend file][3]


  [1]: https://i.sstatic.net/iSREp.jpg
  [2]: https://i.sstatic.net/tulQ8.jpg
  [3]: https://drive.google.com/file/d/1JH-811zHnC1TMx_UGQ5HUolVidJ5ola2/view?usp=sharing