Firefly 4 videos creating content I specifically asked not to

I asked Firefly to generate a video from a still image of some stars and planets (diy mobile suspension of cardboard stars and planets). It does that perfectly, making the stars and planets move very slightly, as asked, but keeps adding some weird fireworks and shooting stars effects. For the next prompt I specifically asked for it to stick to the image as seen, and not add or do anything else. Still, fireworks. Then I specifically asked for it to keep the angle fixed, make the stars move very slightly and do absolutely nothing else. Result: more fireworks. Then I  asked it specifically to NOT generate fireworks or special effects, to use only the given image and not add any effects. And still: fireworks, more fireworks. What is up with that? Four generative requests wasted on ignored prompts.