Sitecore Commerce 9 - search result skipping Catalog items

I am working on Sitecore commerce 9 update-1. Many customizations are already done till now.

For searching I'm using the default SXA Search component.

 

Issue :-

If I do a search by Product ID or Name, search result is always nil.

Please share your thoughts where I can check - why Product items are not coming in search results.

 

And also, what is the best way to include a custom field to search result of SXA search component ?