Domain mapping not working with subdirectory install

hi there,
i have a new problem
i change an addon domain(not root domain) in my cpanel into wp multi site using the subdirectory feature
i could install it alright
i’ve install domain mapping plugin for it too.
but when i add the domain to be map, say abc.com
it redirects back to the root domain site.
the url is abc.com, but the content shown is not new install of map domian.
but content is the content of root domain
how do i solve this problem?

sorry if my phrasing sounds terrible ??