The oil temperature and time required to cook the chicken fully and turn the exterior golden-brown will vary based on the thighs’ thickness and overall size.
Thicker thighs will require a lower oil cooking temperature and longer frying time relative to the smaller and skinnier thighs. If your thighs are particularly small and thin, consider increasing the oil frying temperature and cooking them for less time.
If you are working with really large chicken thighs, you can gently flatten the thickest sections of the meat under plastic wrap to make the thickness more consistent and ensure more even cooking.
Allowing the thighs to rest at room temperature for 30 minutes after they are breaded the second time will help warm the insides of the chicken pieces so that they cook more evenly when fried.