While making a texture pack, I decided to try to animate another texture, the jack o lantern, after I was done with the files and the texture, I went in game and after many different attempts noticed it didn't work. I also tried and old texture pack that used to animate it and it didn't work either.
Here's a pic of the code in the flipbook_textures.json, everything should be labeled correctly.

  And here's the texture that's supposed to show up in game