Regardless of the platform and aim to improve the user experience, social networks usually set some guidelines and best practices to conduct user behavior into constructing a better environment for the community. In Facebook's case, these directions are gathered under their Community Standards and any violation might result in your account being restricted or blocked by Facebook.
Although Facebook doesn’t specifically mention which activities violate their guidelines, penalties are usually related to posting frequency, duplicate content, or other spam or bot-like behavior.
With that in mind, Postcron offers a Delay between posts function, that automatically adds a certain number of minutes between your posts when scheduling the same content to different social accounts, and also a Predefined Times option which allows you to set your favorite times to post and help you avoid posting frequency issues.
It’s also important that you share content that follows the guidelines and is relevant to your audience.
If your account has been blocked or restricted by Facebook, the best way to understand why it happened and solve it is by contacting Facebook’s team.