pickle Okra...Tooo tough

Hello folks, I need help, I tried to pickle okra and after checking out several recipes, I gave it a shot…some of my okra was kike leather while others in the jar were perfact. what’s the deal>> could the okra be to mature or what???

I did pick thru and remoned any okra that seemed to be too mature. yet some still were hard and tough. an then some were perfact.