They both will, it can be husbandry related in that case make a few changes (temps,substrate, downsizing), it can be the wall, which is commonly seen when they are 800/1000 grams. Or it can simply be an animal being overfed that is catching up (too large of preys or too often will do that)
Finally health issue but I think by now you would have noticed.
Fast are normal in older animals as their metabolism is much slower however in younger animal (under 500 grams) it is not as common and often every time link to husbandry.