Problem with Strider Models

I am having a problem with Optifine models, but the thing is that it is only for striders. I have tried making my own strider model packs and using others but they don't work. Models for other mobs are working so its a little weird. I have tried using packs made by others like Shellnik by PixalThePixeled or Striders with Hats by Siscu. What happens is the textures work but not the models. I don't know if this is a change with Optifine that changed the strider's .jem file name or what but it seems to only be with striders. If anyone knows why this would be, please tell me because I'm trying to work on a pack that changes strider models but the models aren't working.