Auto post not working consistently

Only use it to post to FB. Had stop sharing for many weeks. Turned it back on. Had to reconnect my FB account. Your plugin showed in how many hours it would post. Posted a few manually and those worked. But only one has it posted automatically. And no matter how many times I refresh it doesn’t say in how many hours it will post again. Most times it doesn’t say. Infrequently it will. What’s going on?

https://www.ads-software.com/plugins/tweet-old-post/