Link Option

Hello, I'm struggling with the following problem: I have a page index.html with various sections, which are also linked in the Navbar. There are also two other subpages with the extension * .html. If I link now from the page index.html to a subpage *.html and from there directly back to a section on index.html everything is ok. However, when I want to link to a subpage * .html again, I always end up at the index.html. What am I doing wrong in the link options ???