The most likely reason for this complaint is the misuse of the feature.
DoH wraps DNS requests inside standard HTTPS web traffic, making it impossible for firewalls to distinguish your DNS queries from regular web browsing. Top Performing DoH Providers https://1.1.1 (Fastest global response times) Google: https://dns.google (Highly reliable routing) v2ray slow dns server
In this configuration, Chinese domains use a fast local DNS resolver, while non-Chinese domains use encrypted DNS through the proxy. V2RayA's split DNS architecture similarly separates internal DNS for domestic domains from external DNS for foreign domains. The most likely reason for this complaint is
Standard UDP DNS is often throttled or intercepted by firewalls (the "Great Firewall" is notorious for this). Switching to ensures your queries are encrypted and move through the same port as standard web traffic, preventing interference and speeding up resolution in restricted environments. Step C: Optimize the "Rules" Section Step C: Optimize the "Rules" Section