404 page return only with iOS devices

Question

I published an app on www.yoohood.fun, created with the create-React-app, using an AWS server, and when the user accesses with the Facebook account, it is redirected to the /Sync folder. However, when someone accesses by iphone, either by Safari, or by Chrome, or by safari in other Vices the return is a 404. Can someone give me a light on what problem might be happening?

The Nginx is like this:

server {
    listen 80;

    server_name 54.233.226.167 yoohood.fun www.yoohood.fun;

    location / {
           proxy_pass http://172.31.0.12:5000;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection 'upgrade';
           proxy_set_header Host $host;
           proxy_cache_bypass $http_upgrade;

    }

}

server {

    listen 443;

    ssl on;
    ssl_certificate /etc/ssl/https/ssl_bundle.crt;
    ssl_certificate_key /etc/ssl/https/server.key;

    server_name 54.233.226.167 yoohood.fun www.yoohood.fun;

    location / {
           proxy_pass http://172.31.0.12:5000;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection 'upgrade';
           proxy_set_header Host $host;
           proxy_cache_bypass $http_upgrade;

    }

}