Happeo keeps all user data up-to-date, but sometimes there might be a change to a user which is not propagated to Happeo. There may be multiple reasons for this, most notably the change of Happeo synchronisation admin rights. In these cases it's handy to update all users manually.
To do this, you need to have admin permissions, open up admin panel and go to Users -section. From here, simply select "Update all users", from the top menu. The update may take up to 4 hours to complete.