There are 2 reasons why you may not see your recorded calls:
#1. Recorded calls can take up to 2 hours to appear in the portal.
#2. You do not have permission to the extension on which the recorded call took place. If yoiu do not have permission to the extension (set on the extensions page) then you will not be able to review the recorded calls of that extension.
If you have waited longer than 2 hours, and you have the proper permissions - and calls still do not appear in the Recorded Calls section, please contact support.