You can’t do anything with the Login Bar, that is a closed box to code.
As for your duplication issue, check your pages in your Wix Members app as it is just displaying the pages from there.
You can show or hide pages from there through the Wix Members own page settings.
As this is not a code related issue, please go through Wix Support for more help with this as this Corvid Forum deals with all code related issues only.
https://support.wix.com/en/article/contacting-wix-customer-care-for-support