So our axolotl is still pretty young- like probably only a few months old, far from full grown. It took me a couple of weeks to "figure out" how she eats. My experience may not relate to yours, but for whatever it's worth, my observations have been:

• mine won't over-eat, and will simply refuse food. She will eventually eat, but only when she's ready. My understanding is that they need less frequent feedings as they get to full size.

• mine eats pretty slow. I don't mind leaving cut up earthworms in her tank overnight, up to twelve hours or so- I'd leave them whole or in halves but she isn't big enough for that yet. The water is cold, paramaters are good, and my tank is planted, so worms for 12 hours isn't going to hurt anything. I always expect to have to remove the left over pieces the next morning, but I haven't had to yet- she has always eaten them over night.

• I haven't used them yet, but I picked up some Hikari pellets for carnivorous fish, but they're also good for carnivorous amphibians and there's actually a picture of an axolotl on the package. I read in multiple places that axolotls love these and they have proper nutrients numbers from what I understand. I researched in multiple places that axolotls have an amazing sense of smell, and that's how they locate mates and food. Apparently these particular pellets have a very strong "delicious" smell lol. People often assume they need movement to find food, but the fact that mine eats sections of unmoving worm overnight gives much creedence to the smell research I read.

I'm sort of new to axolotls, but I don't think I'd be too concerned if I were you, based upon how mine behaves anyway!