Save home to force removal of first slug.

I don't know what problem you're experiencing by just looking at the title, but it sounds slightly similar to something I looked at in the past.

Please mind the fact that a page's path generation as related to whether it's a child of home is a monstrosity that is being handled by signal handlers.

Have a look at:
https://github.com/divio/django-cms/pull/1647
https://github.com/divio/django-cms/issues/1555
https://github.com/divio/django-cms/issues/1620