Why can't I see an attached document in the KB when I enter normally and can see it when opening the article in the Help Center?

Why can't I see an attached document in the KB when I enter normally and can see it when opening the article in the Help Center?

Scenario:
  1. Create article in KB
  2. Attach a document as downloadable attachment
  3. Publish it for All Users
  4. Go to the article
  5. Login to the portal as a customer
  6. Navigate to the article
Expected result I can see the attached document as an agent in Zoho desk when navigating to the KB (step 4); I can see the attached document as a customer when in the Help Center and navigating to the article (step 6)
Actual result As an agent I cannot see the attachment in Zoho desk when navigating to the KB (step 4); I can see the attached document as a customer when in the Help Center and navigating to the article