Welcome to PT!

I'd have another vet check the poor little guy over ASAP, like tomorrow. It could be that he's just groggy from the anesthetic, but I'd want to find out just what the idiot vet did to him. Cryptorchid males whose testicles haven't descended require more extensive surgery, so maybe that's what happened--but the vet and staff should have told you if that was the case.

I hope little Rocky gets better soon!