Magento 2 – Aftert importing products with CSV number of products imported is wrong

I have imported products via CSV file upload using Magento 2 import. In total I have imported 50401 products.
I have a problem, the number of imported products is not equal to the number of found records I see in the CATALOG -> PRODUCTS section.

The following images explain better the problem:

CATEGORIES section in Magento backend

Select count products from database

PRODUCTS section in Magento backend

As you can see the number of products in the PRODUCTS section is 50551, more than the imported products. If I clean the cache or perform an index update, this number changes but it is never equal to the real number of products loaded.

Does anyone have any idea what happened? Thanks to all!