The proxy has a policy to block access to any website that belongs to a category, even though the policy trace shows that the website belongs to the category but the access does not match the rule.
The policy is written manually by using a CPL. For example:
DENY category="File Storage / Sharing"
Product version: 6.7.x and 7.x
Environment: Explicit and Transparent Proxy.
The issue is due to the category name that is not exactly the same based on the example given, the "File Storage / Sharing" has a space in between.
The category name should be exactly the same and based on the example given above, the "File Storage / Sharing" should be written without the space - ""File Storage/Sharing".