Only Clients with a VPN can access my website [closed]

I have a simple website set up on port 80 and set up port forwarding correctly. It seems to be the case that only clients running a VPN can access the website. Others who try to connect normally either get a 'The page took too long to respond' or the page loads indefinitely. My website is set up using Node.js, where I am sharing a simple .txt file

const http = require('http');
const fs = require('fs');
http.createServer((req,res)=>{
    const readStream = fs.createReadStream('./example.txt')
    res.writeHead(200, {'Content-Type': 'text/html'});
    readStream.pipe(res);
}).listen(80);

Local devices can connect normally, even when i ask for the public ip. I tried using mobile Data on my phone, and that didn't work either. Is this some sort of ISP issue?