My experience with peppers is that they ripen inside the same as outside. I never have peppers the first summer. I start them in the ground and transplant to pots in the fall.
It might be that your inside is too dry and they are drying before they mature. Take it back outside when nice weather returns and see if they still wrinkle too soon.
Or it just might be your plant. Seeds are never exact duplicates of their parent.
Daisy
