We do speed tests hence we saw the issue. See https://github.com/golang/go/issues/47840 https://github.com/golang/go/issues/47840 Yeah I agree this is a edge c

We do speed tests hence we saw the issue. See https://github.com/golang/go/issues/47840 https://github.com/golang/go/issues/47840 Yeah I agree this is a edge case, 99,99% of Caddy users don't push so much data ;) But Caddy can't be used as a big files download server for instance, unless sticking with HTTP/1.1 (that and sendfile + kTLS not been supported last time I checked?) (at least with a single http instance). Another issue for HTTP/3 is https://github.com/lucas-clemente/quic-go/wiki/UDP-Receive-Buffer-Size https://github.com/lucas-clemente/quic-go/wiki/UDP-Receive-B... Current Linux in WSL for instance has this issue. This will probably resolves over time as more and more Linux distros will take HTTP/3 requirements into account.