I had gotten 5 Panda Cory's from a lfs that seems to be popular and really knows what there doing, however in my care, all the fish I've had have been pretty hardy. And yet I had one die and got him replaced for free. And over the next 2 months. Some fell under extreme fin rot. One had a fungal infection. And slowly 5 died over time with small things wrong here and there. I have one left. And he's healthy like the rest of my fish.
IMO. Cory's just seem to be.... Brittle fish lol. For lack of a better word.
And I had a few lose whiskers. Start healing. And die... Never knew why... Just something they do I guess...