I have also encountered the same problem. Have you found a solution

Yes, strange issue often show up when there are two or more content filters or even Network Extensions that are try to delegate or handle the same traffic so this does not surprise me. I would like to know what caused this problem? Is there no solution?

Thank you for your reply. There are multiple content filters on my computer. I want to know if there will be conflicts. Once tow content filters are installed at the same time, some computers may have a problem with DNS resolution. A large number of "CFIL: Falied to create UDP flow" logs will appear in the console. Then, if I uninstall one of the content filters, the computer will return to normal, and the above-mentioned logs will no longer be displayed. Additionally, in most computers, I haven't observed the above-mentioned logs. Is there a way for me to reproduce the issue you mentioned?

default 2023-04-17 13:40:21.471858 +0800 kernel cfil_sock_udp_handle_data:6495 CFIL: Falied to create UDP flow error 2023-04-17 13:40:21.471879 +0800 mDNSResponder sending to <IPv4:BBEgZPbq> failed: [32: Broken pipe] default 2023-04-17 13:40:21.471894 +0800 mDNSResponder [Q32291] Sent 37-byte query #5 to <IPv4:BBEgZPbq> over UDP via en0/6 -- id: 0x1886 (6278), flags: 0x0100 (Q/Query, RD, NoError), counts: 1/0/0/0, BBWaCfNd IN HTTPS? default 2023-04-17 13:40:21.471934 +0800 kernel cfil_sock_udp_handle_data:6495 CFIL: Falied to create UDP flow error 2023-04-17 13:40:21.471987 +0800 mDNSResponder sending to <IPv4:BBEgZPbq> failed: [32: Broken pipe] default 2023-04-17 13:40:21.472002 +0800 mDNSResponder [Q20160] Sent 37-byte query #5 to <IPv4:BBEgZPbq> over UDP via en0/6 -- id: 0xAF28 (44840), flags: 0x0100 (Q/Query, RD, NoError), counts: 1/0/0/0, BBWaCfNd IN A? default 2023-04-17 13:40:21.472042 +0800 kernel cfil_sock_udp_handle_data:6495 CFIL: Falied to create UDP flow error 2023-04-17 13:40:21.472067 +0800 mDNSResponder sending to <IPv4:BBEgZPbq> failed: [32: Broken pipe] default 2023-04-17 13:40:21.472068 +0800 kernel PMRD: kIOMessageSystemWillPowerOn to com.apple.iokit.IONetworkingFamily default 2023-04-17 13:40:21.472100 +0800 mDNSResponder [Q21000] Sent 48-byte query #7 to <IPv4:BBEgZPbq> over UDP via en0/6 -- id: 0xBB72 (47986), flags: 0x0100 (Q/Query, RD, NoError), counts: 1/0/0/0, BBAdvaQU IN HTTPS? default 2023-04-17 13:40:21.472129 +0800 mDNSResponder [R850] getaddrinfo stop -- hostname: <mask.hash: 'IUEDPruiVj0cmSGVftMKvQ=='>, client pid: 1417 (Core Sync) default 2023-04-17 13:40:21.472137 +0800 mDNSResponder [Q35650] Keeping orphaned querier for up to 5 seconds default 2023-04-17 13:40:21.472148 +0800 kernel cfil_sock_udp_handle_data:6495 CFIL: Falied to create UDP flow default 2023-04-17 13:40:21.472156 +0800 mDNSResponder [Q41] Keeping orphaned querier for up to 5 seconds error 2023-04-17 13:40:21.472171 +0800 mDNSResponder sending to <IPv4:BBEgZPbq> failed: [32: Broken pipe] default 2023-04-17 13:40:21.472198 +0800 mDNSResponder [Q32014] Sent 48-byte query #7 to <IPv4:BBEgZPbq> over UDP via en0/6 -- id: 0x1406 (5126), flags: 0x0100 (Q/Query, RD, NoError), counts: 1/0/0/0, BBAdvaQU IN A?