Symptoms
The expected behavior is that the "Default Action" will determine what the default action is when you look at a URL Filter and the Filter Action has not been explicitly defined. However, if a category sets the default action to "block", URL Filter will be configured to "allow" the URL Category even though it was set to "block" by default.
Impact
URL Filter will be configured to "allow" the URL Category even though it was set to "block" by default. This could cause the URL filter to allow websites that the admin thought should be blocked.
Conditions
Create a new category URL and set the default action to block.
Workaround
Double check in the URL Filter that the categories that should be blocked are actually set to block. These categories can be changed manually from the URL Filter page if they are not correct.