For a longtime Techlivewire.com had an overlapping header with content problem where the top part of a main single post page or a page isn’t visible. It took me a while to figure out but I finally fixed the problem. All I had to do was find the page .single in CSS and add the CSS Padding-top: 130px; and that did it. Just to be safe I did it for all mentions of single post or page in CSS since there were multiple CSS for single and page. I also had to do the same for the responsive part of the CSS so it adjust just fine in responsive mode too. It may not be as simple as it was for me in your case depending on the Theme you are using and how whoever made it decided to code it but if you analyze your CSS you should be able to fix this issue just like I did. My theme didn’t come with a fixed header, but I added it myself. Right after adding my own Fixed header with CSS is when this problem of overlapping content started.