Since chrome implemented QUIZ to server web requests, it has been a dark period for IT administrators because normal web filter won’t work to filter google/youtube sites. You may check more details at Why is Google’s QUIC Leaving Network Operators in the Dark?   A protocol description of QUIZ can be found at: https://www.chromium.org/quic

Our team has worked out solutions to block QUIZ, so you can get web filter back to working.

For WFilter Enterprise and WFilter Free, you simply need to block UDP port 443 in your router/firewall. Steps to block udp ports can be found at here: http://wiki.wfiltericf.com/Block_udp

For WFilterROS, please check this post: Do not forget to block QUIZ to block youtube and other google sites.