Saving your teamwork file, just saves the local copy. It doesn't send the changes back to the teamwork file on your BIM Server. So the project on the server will only have the information from when you last sent your changes to it.
It may be a good idea to join the project as another (temporary) user and see what the latest iteration is. You could try this from the same computer, but use another instance of ArchiCAD. If it looks up to date using the other user, then you could simply reload the project from the server, using your usual user log in.
If not, then it's time to start looking at your backups. If Rollback didn't work you could look at downloading the BIM Project backup and re-importing it to your server. Or open up a pln backup and re-sharing it.
In any case, I'd make a copy of the default project folder while you were doing this, just in case you need to get tech support from Graphisoft. You can find the path in your BIM Server Control Center via the Preferences button.
Good luck!
Cheers,
Link.