On the same PC: Ad Block works in Firefox but not on Chrome.

Question

Chrome skips Ad Blocking and displays the ads. 
 Ad-Blocking works: 
 
 UTM Policy Checker 
 Firefox as browser 
 
 Sophos UTM 9.410-6. 
 All happening on the same PC running Ubuntu 16.04. (Tested chrome on another Windows PC behind the same UTM. Blocking works as expected...) 
 As this sounds not logical to me: See screen video at https://youtu.be/D5gqOmnB81M

sachingurung · Answer

Hi Jasime, 
 Configure a FW-Rule to drop UDP 443 services. Also, check out the below link which has some useful tricks. Any help with that? 
 https://community.sophos.com/products/unified-threat-management/f/web-protection-web-filtering-application-visibility-control/46207/speeding-up-webbrowsing-by-blocking-advertisers-and-trackers 
 Thanks

BAlfson · Answer

Jasmine, I've moved this thread to the Web Protection forum. 
 Sachin's approach will block Chrome from communicating on UDP 443 with Google servers, thus forcing Chrome to use TCP 443. An alternative might be to use Standard mode and add UDP 443 to 'Allowed Target Services' on the 'Misc' tab of 'Filtering Options'. If you try that and it works, please let us know if the Proxy can do HTTPS with UDP 443 traffic. 
 Cheers - Bob