My links are behaving funny

Hello everyone, I’m having a problem with my wordpress website and I’m looking for answers.

I changes my permalink. Now my pages are something like myname.com/about instead of myname.com/about.php. I have no problem with this, it’s just that whenever I go to a page like ‘about’ and now click on another page like let’s say ‘services’, it takes me to myname.com/about/services. How do I resolve this problem? Thanks in advance.