Nuxt.js无法从不同端口的Express后端加载数据问题排查

我的NUXT SSR网站https://tejasjadhav2001.tech部署在https://34.93.29.137:3333，REST后端的Express.js服务器部署在https://34.93.29.137:3000。https://34.93.29.137:3333通过Nginx代理到根域名tejasjadhav2001.tech。

前端API调用代码 #

getArticles(id) {
    return axios({
      method: "GET",
      url: `https://34.93.29.137:3000/api/v1/blog/`,
      withCredentials: true,
});

后端CORS配置 #

尽管已在后端配置CORS，但请求后端时仍出现CORS错误：

const corsOptions ={
    origin:[
            'https://34.93.29.137:3000/',
            'https://34.93.29.137:3333',
            'https://34.93.29.137',
            'https://tejasjadhav2001.tech',
            'http://tejasjadhav2001.tech',
    ],
    credentials:true,            //access-control-allow-credentials:true
    optionSuccessStatus:200
}
console.log("Using cors options");
app.use(cors(corsOptions));

特殊现象 #

手动通过浏览器调用后端API（如https://34.93.29.137:3000/api/v1/blog），接受SSL警告后加载数据，此时再访问https://34.93.29.137:3333或https://tejasjadhav2001.tech，网站能正常加载后端数据。

Nginx配置 #

a@instance-1:~$ cat /etc/nginx/sites-available/default 
server {
        listen 443 ssl;
        server_name tejasjadhav2001.tech www.tejasjadhav2001.tech;

        gzip on;
        gzip_types  text/plain application/xml;
        gzip_proxied    no-cache no-store private expired auth;
        gzip_min_length 1000;
    ssl_certificate /etc/letsencrypt/live/tejasjadhav2001.tech/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/tejasjadhav2001.tech/privkey.pem; # managed by Certbot
    #ssl_password_file /etc/ssl/certs/pass.pass;
        ssl_protocols  TLSv1 TLSv1.1 TLSv1.2;
        ssl_ciphers HIGH:!aNULL:!MD5;

        # This is a cache for SSL connections
        ssl_session_cache shared:le_nginx_SSL:1m;
        ssl_session_timeout 1440m;

        rewrite ^/(.*)/$ /$1 permanent;


        location / {
                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;
                proxy_redirect          off;
                proxy_buffering         on;
                #proxy_cache             STATIC;
                proxy_cache_valid   200 1d;
                proxy_cache_use_stale   error timeout invalid_header updating http_500 http_502 http_503 http_504;

                proxy_pass              https://34.93.29.137:3333;
                proxy_read_timeout  1m;
                proxy_connect_timeout   1m;
        }

请问该问题是由CORS还是SSL证书导致的？

内容的提问来源于stack exchange，提问作者Tejas Jadhav