Sometimes, Facebook may misidentify your posts as Spam, or your posts may violate their community standards.
In order to fix this, Facebook provides an option that you may take advantage of. This option is to request review of the posts. You may do this by navigating to your Facebook account and viewing the posts that were rejected. Those posts will then have a Review option that you can select to have Facebook take another look. This might take some time, but Facebook will respond.
To avoid these issues in the future, take a look at Facebook's community standards.