Post Schedular

I have a couple of blog sites and facing an issue in all of them. I like to post every 4 days and like to prepare content in advance. I normally schedule 7-8 posts in advance.

I am not a technical person so don’t understand how the scheduling works. I just select the date I would like the post to get published on the ‘add new post’ page. But 90% of the time it shows ‘missed schedule’ and the post does not get published. Have to go and do it manually later once the date has passed.

Can someone help fix this issue. What is the use of having a good feature like that but one that doesn’t work. It is happening on all my sites so there is definitely an issue.