How do I troubleshoot specific Products missing from Commerce Search? Using Commerce Kickstart 2

Having a situation where certain Products simply do not appear in the Search results. Is there a way to troubleshoot specifically -why- certain products (or other content) are not appearing in the search index?

I looked through the search_api_db_product_display table and sure enough, the missing node is -not- there.

So: Is there a log or table which displays each node and index term and/or -why- a particular node was included/excluded?

Just to be clear: If I enter the URL for the Product directly, it displays fine.

ALSO: I can search from admin/commerce/products and the Product shows up as well as from admin/content.

Perhaps related: There seems to be a known issue where adding new products does not automatically update the index. But I have cleared the index and rebuilt several times and it makes no difference.
Not sure if this is proper 'etiquette' but here is the solution for -this- problem:

My Product Display has an Entity field which displays a list of 'related products' -- a common enough situation in a Shopping Cart system. The related products are a View which displays products linked to the parent product NID.

Like most sites, I imagine, the Index excludes unpublished products.

Apparently if any one of the Related Products is unPublished, this affects the Commerce and/or SOLR Search index for the -Parent- product. IOW: if any child product is unPublished the index skips the -parent- product as being 'unpublished'.

Not sure which module is at the root of this... or who to notify... but if the Commerce Guys monitor, this is a real 'gotcha'. I've run into this many times in Drupal where SQL Queries are not 'isolated' from one another... ie. a child view will affect a parent query.