bot not work some time

Hello and greetings.
As all of you know wptelegram plugin automatically sends website topics and posts into a telegram channel as it released into the website.
We used to using wptelegram for our website and its really efficient for us but it has a simple problem and i really cant find out where is the problem!
It always works in a correct way but the problem is that,sometimes it missing some posts and doesnt send the notification in telegram.
I was wondering does anybody face with this problem and if yes how to solve it?
Thanks a lot.