If you add a new contact in Outlook Web App, the contact is added to your contact folder, not the Outlook Custom Manager folder. So the contacts will not show in the OCM desktop application. It’s recommend that you import the contact again in the desktop application.
Using it in Outlook Desktop is fine if it would stop crashing and be more reliable. Also, if I can contacts via the Desktopn app and go home to another PC with the desktop app and OCM, it will be there?