Limiting search to a site collection NOT working

I am trying to limit my search results to a specific site collection, but it is NOT working.

I have the following configuration:

1- Root site collection

2- /sites/teamsitecollection

3- /sites/teamsitecollection/searchcenter

Basically I am trying to configure search center to NOT display any results from the Root Site collection when a user queries from from /sites/teamsitecollection.

what i did.

1. 
   

   Configured the search settings /sites/teamsitecollection to point to the following results page: /sites/teamsitecollection/SearchCenter/results.aspx.

   
   


2. 
   

   On the /sites/teamsitecollection configured a RESULT SOURCE with the following query transform: {searchTerms} Path={SiteCollection.URL}*

   
   

However this configuration continues to display results from the root site collection. any ideas?