Thank you for reaching out to the Community. It sounds like you may have exported your Deleted Unsubscribed contacts. This will only export the unsubscribed contacts that have been deleted from your account. If you're looking to export your contacts in your unsubscribed list, you must first select all of the email addresses by clicking the check box.
Once you select these contacts are selected, click on the Export button, and choose Export selected unsubscribed.
Once these steps are taken you can then download your full unsubscribed list under the Activity tab in your Contacts.