Magento 2:Your web server is set up incorrectly and allows unauthorized access to sensitive files. Please contact your hosting provider

I’m struggling trying to solve this very annoying problem on my Magento 2.3.3 store. Today I forced the SSL on the website (I did it that by enabling the https on the unsecure URL). After 10-15 mins, while I was editing some coupon codes, I got this notification on my backend: Your web server is…