Cannot download file while headless: true, works when headless: false [Puppeteer] - node.js

Question

Im running a script that logs into an authenticated session on a website and clicks a button to download an excel file. Im able to run it with no problems while headless: false, but when headless:true, the file does not download.
My research suggests that the browser is closing before the download completes possibly? Ive added a wait of about 15 seconds, which is much longer than it should need to download the file, but still not getting anything. Another solution I tried was manually removing the HeadlessChrome substring from the userAgent in case the site was blocking it, but that didnt work either. Is it okay to use headless:false in a script that is used in a production web application deployed on Heroku?
async function getData () {
try {
const wait = (ms) => new Promise(resolve => setTimeout(resolve, ms))
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto('<url>');
//login
await page.type('#username',username);
await page.click('#signIn');
await wait(4000)
await page.type('#password',password);
await page.click('#signIn');
await page.waitForNavigation();
await page.keyboard.press('Enter'); //click out of any pop up
// //go to merchandising page
await page.click('#m_69-link');
await page.waitForSelector('#ExcelReportButton', {visible: true})
//click on export as excel icon
await wait(4000)
await page.click('#ExcelReportButton');
await wait(15000)
await browser.close();
} catch (error) {
console.log(error)
}
};

Answer 1

try by adding additional headers, it worked for me:
await page.setExtraHTTPHeaders({
'Accept-Language': 'en-US,en;q=0.9'
});
await page.setUserAgent('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36');