Why do chicken wings turn chewy if cooled between cookings?
Your temperature is too high. Go for 78ºC (172F) instead of 82ºC. 3 hours seems a long time for chicken wings. Get a thermometer and take it out when it reaches 78ºC. After cooling, before frying, do you dry the wings? That could be an important step.

Lastly, instead of frying them as is, try panning them with flour or breadcrumbs.

If you're going to fry immediately, aim for 75ºC instead.