Have you experienced that similar issues with subsite?
In subsite - pages created on main site are appearing on subsite.
Somehow, pages which created in main site are wrongly appearing in subsite.
This is intermittently happened to me.
Although you have removed pages, those pages are back in subsite.
The pages are cloned with subsiteIDs.
// Include any relevant code. If you have a lot of code, link to a gist instead.