Why does my website keep showing old index.html, style.css, app.js…?

I have a problem that I can’t solve. I’m new to web-developing, and I coded my first web-site, bought a domain and hosting, and added my files to the public.html folder.

Whenever I change the code, either in css or js and delete the previous files in the public.html folder and then add new ones under the same name with which the code was changed, when I load the site, either by phone or desktop the site looks and all elements remain the same that I haven’t changed the code at all, if I change the names of the html, css and js files, I link them and insert them that way, it only shows me a list of files in the public.html folder. The only time the code update works is when I open the site in incognito mode for browsers.

My assumption is that there are some problems with cookies and cached data, but even when I delete them in browser, the code is not updated but the site uses old files.

Does anyone know some solution to my problem, otherwise I use domain and hosting from hostinger and I haven’t changed any settings in domen and hosting since I bought it.

Thank you all.