Festae x firemouth hybrid will probably look very different from this. Whilst its not certain how a hybrid offspring may look like, I doubt two so colorful cichlids can produce something this drab.

No, the body isn't too round for it to be some sort of Amphilophus.
Not a lot of cichlids sport this color - at least, not many that I know of. There's either the midevils, pink convicts or severums. The head doesn't curve down as in a severum, and the shape is nowhere near round enough. Conversely, not a pink convict since their body is more elongated, plus different shade of pink.
So yeah, the body shape, coloration, and all that points to it being a red devil/midas/midevil.