Index entries less than Expected entries after performing rebuild index. Why?

[bobbingwide]

On blocks.wp-a2z.org the Index entries is 1186, but Expected entries is 1188.
Why is there a difference?

The problem is not occurring in the live site. Both values 1072.

[bobbingwide]

Problem Explanation

The oik-loader-10.csv file contains 594 records = 1188.
The last 3 are from the oik-loader-extras.csv file.

The difference is due to the number of index records being created for the oik-loader-extras.csv file not matching the expected amount.
We would expect to see 6 index records for 3 entries but we only see 4.

/wp-json/wp/v2/download_category,0,edd-blocks/edd-blocks.php,easy-digital-downloads/easy-digital-downloads.php
/wp-json/wp/v2/download_tag,0,edd-blocks/edd-blocks.php,easy-digital-downloads/easy-digital-downloads.php
edd-api=products,0,edd-blocks/edd-blocks.php

This is due to the ID zero being used 3 times, but only one record being created.

Created in the index

   [/wp-json/wp/v2/download_category] => Array
        (
            [0] => edd-blocks/edd-blocks.php
            [1] => easy-digital-downloads/easy-digital-downloads.php
        )

    [0] => Array
        (
            [0] => edd-blocks/edd-blocks.php
        )

    [/wp-json/wp/v2/download_tag] => Array
        (
            [0] => edd-blocks/edd-blocks.php
            [1] => easy-digital-downloads/easy-digital-downloads.php
        )

    [edd-api=products] => Array
        (
            [0] => edd-blocks/edd-blocks.php
        )