does my peacock have shellrot, please help,,,,,,Roy?

[Polscot]

so i've had this peacock mantis for about 4 months he seems healthy as a horse, eats well but he hasnt molted once, hes about 5" i caught a glimps of what looks kinda like shell rot on his back just above his eyes, can anyone confirm?

It could just be a battle scar and because of his size it takes ALOT longer to molt but im not sure

if it is, is there anything i can do? dont really want to lose him as hes trained to eat out of my hand now and recognizes me