Scheduled Posts Not Auto Publishing

For authors that submit scheduled posts, they do not trigger the social media auto publish. Normal posts published “by hand” auto-push to Twitter, for example, but when our authors schedule post for later publishing, it isn’t sent out.

I checked and here’s what happens:
Make a new post, set publish date to a few minutes in the future
Check the bottom – the social media auto publish option defaults to no. If I don’t change it, then when the post is published, the post is not sent to Twitter. The thing is, even if I do change it to the Yes and save the post, when it publishes, nothing is sent out via Twitter.

Please help!