Missing Cory's😢

Hi again
I had 6 bandit Cory's bought in 2 groups of 3 that were always hiding and never really seen as 6 especially after plants became established. However as I was never seeing many I did a search during a water change and 3 have disappeared! No evidence of bodies
3 were in the tank throughout the bacterial bloom and ammonia spike I saught advice about a few months ago. Is  it possible they were damaged then? I have never seen any fighting or bullying (have 3 clown loach as well) but as the surving 3 are really hiding most of the time  is this due to stress from others dying and obviously becoming a food source? Should I replace them to give a bigger shoal?
Thanks for any advice.

A few suggestions: could they be in the filter (ie sucked in), buried under the sand/gravel, in the corner of an ornament/cave (sometimes only identified once they're actually moved out of the way, not simply by looking in), or could any larger fish have eaten them?

The remaining cories and the loaches - and all the other fish - would reduce any bodies to nothing in a few days. No fish will turn its nose up at a free meal.

And yes, the remaining cories could be stressed by lack of numbers. My pygmy cories were down to three. I never found any bodies, except for the half cory I found under an ornament which I think I killed by putting the ornament on top of it during a water change  The last 3 hid all the time until I bought 5 more and now they are out all the time.

It is quite possible the deaths were related to the ammonia. Both this and nitrite in the water can shorten the life span of fish.

Cories really do prefer to be with their own species. They will shoal with other species but only if forced to by lack of numbers of their own.

Was in luck and they had masked Cory's which was what I bought as the second group of 3. I now have 9 Cory's hiding as a  shoal😞. Still hopefully all will come out to play when they settle in😁

Trying to Aquamaid but they all seem to be getting on living in the same cave as the 3 survivors, how they fit themselves in I don't know! Managed to count 8 though so not bad  They are beginning to explore tank though but cannot distinguish new from old as the new ones are same size.

Aww it's true for some "the more the merrier"  glad they are out and about.