Sourcefire URL filtering - odd behavior

[David Inabinet]

I'm seeing some strange behavior with our new ASA 5545-X with the Sourefire URL filtering.

I'm intermittently able to get to known bad sites that should be blocked. For example, we are testing the porn URL filtering and our device is configured to NOT allow any Nudity. For some time, I'm able to browse playboy.com or some of the other known bad sites. Then, without any configuration changes, the sites get blocked. It also seems that after an undetermined amount of time, the sites are allowed, at least for the first attempt then they are blocked again - sending users to the block page. 

Also, a few sites (well known Adult sites) are allowed when, clearly, they should be blocked. 

Is anyone seeing anything like this?

[Austin Clark]

running 5.3.  Playboy blocked,  weird url above not blocked the first time. Blocked it the second.  I'm literally, fine with that because I'm going to give the information to peoples managers regardless if they got one free peek or not. 

[bernhard.hoerl]

we had the same issue and got the url filter to work properly with a workaround from tac

by adding a monitor rule with the same categories we tried to block above the block urls rule the filter seems to work as it should. by adding this the website is first categorized and then the blocking rule matches

i hope this was helpful!