ChatGPT recieves 10 elements to analyze and output only 1

I’m sending an input of a json with a few elements in it to analyze and give me a “yes or no” answer to each one. The output should be a JSON with the elements of the input with the AI answer.

Most of the times it works good.
But sometimes it only return just 1 element as an output.

I’ve tried using assitant and the regulat ChatGPT chat.
I’ve also tried modifying the prompt to tell him to return all the elements in his anser.
Still sometimes it returns just 1 element.

**problem 2:
Sometime it also gives me the JSON in a different structue than what i’ve instructed him.

Any suggestions?