I have a problem with hyper training. I sent my Ferrothorn (+ def nature) to Pokemon moon for hyper training.

Its IVs were shit so I used s gold bottle cap but even with its gold bottle cap boost and defense nature it only has a max of 352 defense. According to serebii its max should be 397. Why is it so low?

I have the same problem with my Haxorus. According to serebii its max HP IVs should give it 356 HP but mine only has 292 after giving it a gold bottle cap.

What gives??