Outlook AddIn is not showing up

Hello,

I developed an Outlook add-in and deployed it via the manifest XML through https://admin.microsoft.com/#/Settings/IntegratedApps, assigning it to the entire organization. However, even after more than a week, no one can see the add-in in either the web or desktop app. The add-in is only visible when a user manually adds the manifest themselves, and it appears after restarting Outlook.

I recall reading that deployment can take up to 24 hours, but it's been more than a week now. Does anyone know how to ensure the deployment reaches users without requiring each one to add the manifest manually?

Thank you.