long connection for upload, then Connection drops

[Akim4ever]

Problem:
I noticed that nginx grpc_pass cause connection drop on upload, (example - speedtest). Also i tested this in roblox and getting "please check internet connection" after raound 5-10 sec~

Screenrecorder-2025-04-14-10-26-22-35.mp4

My nginx conf:

server { # HTTP/2 с PROXY Protocol listen 442 ssl http2 proxy_protocol; listen [::]:442 ssl http2 proxy_protocol; # QUIC/HTTP/3 listen 443 quic reuseport; listen [::]:443 quic reuseport; http3 on; http3_hq on; server_name example.com; ssl_certificate /etc/domain/cert/.cer; ssl_certificate_key /etc/domain/cert/.key; ssl_protocols TLSv1.2 TLSv1.3; ssl_ciphers TLS13_AES_128_GCM_SHA256:TLS13_AES_256_GCM_SHA384:TLS13_CHACHA20_POLY1305_SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305; ssl_prefer_server_ciphers on; ssl_session_timeout 1h; ssl_session_cache shared:SSL:10m; ssl_stapling on; ssl_stapling_verify on; resolver 1.1.1.1 valid=60s; resolver_timeout 2s; location /dns1/ { grpc_buffer_size 8k; grpc_connect_timeout 70s; grpc_socket_keepalive on; grpc_read_timeout 1h; grpc_send_timeout 1h; grpc_set_header X-Forwarded-For $proxy_add_x_forwarded_for; grpc_set_header X-Real-IP $remote_addr; grpc_set_header X-Real-IP $remote_port; client_body_buffer_size 512k; client_body_timeout 1h; grpc_pass grpcs://my.domain.com:3001; } error_page 404 502 503 504 = @fallback; location @fallback { proxy_pass http://127.0.0.1:8889; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto $scheme; } # Логи access_log /var/log/nginx/access.log; error_log /var/log/nginx/error.log;

X-ray conf (using 3x-ui)

}, "listen": "10.0.0.19", "port": 3001, "protocol": "vless", "settings": { "clients": [ { "email": "VF", "flow": "", "id": "ca6f6600-5c0c-4b7c-8524-cad5f4fe8ef2" } ], "decryption": "none", "fallbacks": [] }, "sniffing": { "destOverride": [ "http", "tls", "quic", "fakedns" ], "enabled": false, "metadataOnly": false, "routeOnly": false }, "streamSettings": { "network": "xhttp", "security": "tls", "sockopt": { "V6Only": false, "acceptProxyProtocol": false, "dialerProxy": "", "domainStrategy": "UseIP", "interface": "", "mark": 0, "penetrate": true, "tcpFastOpen": true, "tcpKeepAliveIdle": 300, "tcpKeepAliveInterval": 30, "tcpMaxSeg": 1440, "tcpMptcp": true, "tcpUserTimeout": 10000, "tcpWindowClamp": 600, "tcpcongestion": "bbr", "tproxy": "off" }, "tlsSettings": { "alpn": [ "h2", "h3" ], "certificates": [ { "buildChain": false, "certificateFile": "/root/cert/fullchain.pem", "keyFile": "/root/cert/.pem", "ocspStapling": 3600, "oneTimeLoading": false, "usage": "encipherment" } ], "cipherSuites": "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256", "disableSystemRoot": true, "enableSessionResumption": false, "maxVersion": "1.3", "minVersion": "1.3", "rejectUnknownSni": false, "serverName": "rozetkapay.com", "verifyPeerCertInNames": [ "dns.google", "cloudflare-dns.com" ] }, "xhttpSettings": { "headers": {}, "host": "my.domain.com", "mode": "auto", "noSSEHeader": false, "path": "/dns1", "scMaxBufferedPosts": 30, "scMaxEachPostBytes": "1000000", "scStreamUpServerSecs": "20-80", "xPaddingBytes": "100-10000" } }, "tag": "inbound-10.0.0.19:3001" },

I tried different variants with nginx, but nothing solved this (except using proxy pass, but its killing h2, h3 and stream up/one, but packet up on proxy pass looks working fine)
Am i doing something wrong?

[Akim4ever]

Adding
client_max_body_size 100M;
chunked_transfer_encoding on;
Helped