Google云负载均衡器不返回内容编码:gzip

当我直接访问nginx服务器时,我可以看到“Content Encoding:gzip”头(左侧)。

我已经在nginx配置文件中启用了gzip-proxied:

server {

   listen 80;
    gzip on;
    gzip_vary on;
    gzip_proxied any;  // <------ Here
    gzip_types text/plain text/css text/js text/xml text/javascript application/javascript application/x-javascript application/json application/xml application/rss+xml image/svg+xml;

    access_log  /var/log/nginx/access.log;
    error_log   /var/log/nginx/error.log;

    root /usr/share/nginx/html;
    index index.html index.htm;

    location / {
        gzip_static on;
        if ($http_x_forwarded_proto = "http") {
            return 301 https://$host$request_uri;
        }
        try_files $uri $uri/ /index.html;
    }
}

不起作用的相关链接:

Google Cloud HTTP Balancer and gzip

有什么想法吗?