nginx 反向代理，部分链接依旧是原域名，求解

https://dl.isway.cn
需要反代的网站是https://sketchfab.com

所有的模型链接都是原域名，有没有解决办法？
代码如下：
server {
listen 443;
server_name dl.isway.cn;

ssl on;
ssl_certificate /root/nginx/ssl.crt;
ssl_certificate_key /root/nginx/ssl.key;
ssl_session_timeout 5m;
ssl_protocols SSLv2 SSLv3 TLSv1;
ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
ssl_prefer_server_ciphers on;

location / {
proxy_pass https://sketchfab.com/;
proxy_redirect off ;
proxy_cookie_domain sketchfab.com dl.isway.cn;
proxy_set_header X-Real-IP \$remote_addr;
proxy_set_header REMOTE-HOST \$remote_addr;
proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
}

另外
proxy_set_header Host \$host;
加上去后，就访问不了-Bad Request，何解？


谢谢！