Mismatch issues and UCEM
You may encounter a "mismatch" between what you've set in a property hostname via Use Case-based Edge Mapping (UCEM) for an edge hostname, and what's applied in the "use case-based" behavior in the rules in your property configuration.
Here, we describe some of these mismatch conditions, and how to resolve them.
Incorrect mapping from your property hostname to edge hostname
The first step to resolve any mismatch is to make sure that the mapping from the property hostname (your "vanity hostname") to the edge hostname in Property Manager is accurate. This mapping must match the DNS CNAME record that translates your vanity hostname to the edge hostname that was generated.
Does your UCEM setting match the use case-based behavior?
With Download Delivery (DD), what you've set for the Use Case: Download Mode and the Optimize for Foreground Download setting must match. For example, your DD configuration has set "FOREGROUND" as the UCEM for the edge hostname. So, Optimize for Foreground Download must be set to "On" in the Content Characteristics behavior in the Default Rule.