I have created a website using HTML, CSS, and JS. My website has a navbar, but it doesn’t load smoothly when the page load

I have created a website using HTML, CSS, and JS. My website has a navbar, but it doesn’t load smoothly when the page loads. I am dynamically loading the navbar on each page using JS code. Is this usage incorrect? My project is a medium-level project. Could you please help me?

Would the navbar be smoother if I add it to each page?