Thank you for posting your question here, I will try to answer it to the best of my abilities.
It could be either because of soft tissue
damage which hasnt healed yet or because your tendons have gotten stiff and they still have loosened up yet, for both of these problems you need physiotherapy
. Also you need to continue your foot exercises, to strengthen your muscles, this is essentially a type of recuperation that your foot needs, it cannot be rushed. It will heal but slowly.
I hope this answered your question.