The faces are all disfigured and will not generate clear facial characteristics. This is horrible for images needed with faces. and doesn't match the "examples" that Firefly advertises.
If you can share your prompts and sample images, we can potentailly give you some advice on changing the prompts (sharing a link to one would be especially helpful).
Distorted faces used to be a huge problem with all AI image generators. Things have gotten better over the past year, but still some distortion occurs in faces and hands. I recommend whenever you encounter distorted results, use the "thumbs down" symbol and then add feedback checking "distorted results":