nextSibling() issues

I’m stuck on an issue that I posted in Github, if anyone has idea’s it would be much appreciated :

I looked at dump(page) and it has a path attribute set to :
#path: “/home/pz/Code/pp/user/pages/”

When I look at the source code I see that nextSibling will return $this if the path is not in the collection so it looks like the current page object only holds one item. What’s not obvious is that I have another taxonomy which does render a complete collection with the twig template.