Problem with ajax in WP

Hello

I have very important question. I Hope so you help me ??

I have script logged by ajax. Everything is good but sometimes functions don’t work for me.
I get only information ” 0 “. When I clear cache that later all working.

In my site I have other script with ajax ex. load more posts and this always works fine.

Please help beacuse I don’t now why this the happening.

Thanks ??