我的NginX / php-fpm / Laravel堆栈有问题。post body的内容随机出现在响应中，产生无效的JSON。请求示例：

POST / HTTP/1.1
Accept: application/json
Content-Type: application/x-www-form-urlencoded; charset=utf-8
Host: host
Connection: close
User-Agent: Paw/3.2.1 (Macintosh; OS X/11.2.1) GCDHTTPRequest
Content-Length: 9

test=test

回复：

HTTP/1.1 500 Internal Server Error
Server: nginx/1.14.0 (Ubuntu)
Content-Type: application/json
Transfer-Encoding: chunked
Connection: close
Cache-Control: no-cache, private
Date: Tue, 16 Feb 2021 07:46:25 GMT

test=test{"error_message":"The POST method is not supported for this route."}

错误是正常的（这个URI没有POST路由）。但是正如你所看到的，帖子正文出现在响应中。（随机，5次请求中有1次可以正常工作）
它不是来自Laravel堆栈，我通过在index.php顶部设置var_dump / die来测试它（在Laravel加载之前），同样的问题发生了。
有什么见解吗？
谢谢
我的NginX配置：

server {
        access_log /var/log/nginx/access;
        error_log /var/log/nginx/error;

        root /root/devs/peps/www/public;
        index index.php index.html index.htm index.nginx-debian.html;

        server_name server_name;
        underscores_in_headers on;

        location / {
                try_files $uri $uri/ /index.php?$query_string;
        }

        location ~ \.php$ {
                fastcgi_split_path_info ^(.+\.php)(/.+)$;
                fastcgi_index index.php;
                include fastcgi_params;
                fastcgi_param SCRIPT_FILENAME /var/www/html/public$fastcgi_script_name;
                fastcgi_param PATH_INFO $fastcgi_path_info;
                fastcgi_pass 127.0.0.1:9002;
        }

        listen [::]:443 ssl;
        listen 443 ssl;

    ssl_certificate [path to cert]
    ssl_certificate_key [path to privkey]    
}