There have been many past reports about sync issues and often it's hard to determine whether a sync problem (if there is one) lies with the Mobile or Desktop app.
To help find out where the issue might be here's what you can do. Open a web browser to http://documents.logos.com and sign in using your Faithlife account. Once signed in you can see all of your synced documents.
If the documents shown at http://documents.logos.com match your Desktop app but not your Mobile app, there might be a Mobile sync issue (or a network problem). If your documents don't match on Desktop, it's likely a Desktop sync issue.
Here's a screenshot of the Documents currently available at http://documents.logos.com :
