It works absolutely fine with scheduled wordpress posts. it works with amy kind of posts.
Our plugin posts to all configured social networks at the time post goes live. Technically speaking our plugin is hooked to the event of changing post status from whatever to “Published”. This event is triggered when you hit “Publish” button, when you post on your site from email, when you publish post from your iOS/Android Device, and when scheduled post becomes live.
Please check the Log/History tab and let me know what do you have there.