Webfilter profile with static URL's sometimes still blocking

[Bold_Eagle]

I have a Web Filter Profile with defined static URL's, I still see sometimes a defined URL blocked by the profile.

Does the Web Filter do some check's if the URL is healthy?

Does it do DNS resolve checks?

URL example:

*.nssvc.net, normally reg.nssvc.net will get through but we had a situation that it got blocked sometimes and after a while it got totally blocked. 

[Yurisk]

Nope, unless you are also using DNS filter. URL is sent to FortiGuard servers (or compared to the local cache) for the rating. Cannot know of course what FortiGuard servers are doing with it, but they return to the FGT only rating/category. 

[Bold_Eagle]

Thanks Yurisk for your reply.

But how can this be explained?

URL specified is *.nssvc.net

First it is always allowed, not showing in the pictures below.

After a while it got some blocks.

The the blocks rise and eventually it got totally blocked.

Thanks.