I found it odd when I first breed a pet of mine, it had only one shown gene when both of the parents had several strong genes.
I decided to just sell the little critter since I had another one about to hatch.
When the pet sold however, they had all but one gene showing.

I am not looking to get the critter back, I just wanted to tell you guys about the glitch.

Here is the sylestia which it happened to

It's because of the Re-Generating.