Wordpress permalink one page opens Home instead of actual page

Question

I have following weird problem in Wordpress using permalinks. When I use the default setting for permalinks, everything works just fine. But I want to use the post name as permalink. When using the post name, one link opens the home page instead of the actual page.

Manually changing the permalink in the page settings leads to a 404 Error. I dont think this is the problem but the links form the pages have some similarites:

Home page: www.website.com/name1/

Site with problem: www.website.com/name1/index.php/name1/

What makes it even worse: when i set the parent of the page to home, everything works.

Answer 1

Changing the permalink manually to another string worked in the end.

Might be a bug from wordpress with same names.