What is the problem when querying with custom taxonomies?

Question

Taxonomy

I have a section of code where records are requested

$posts = query_posts($args);
print_r($args);
print " number of posts=".count($posts);

$args is created based on GET parameters. Next, here is the debug print
1. request institution type 3 in the country Russia - empty

Array
(
    [paged] => 0
    [posts_per_page] => 10
    [post_type] => institution
    [tax_query] => Array
        (
            [0] => Array
                (
                    [taxonomy] => institutions
                    [field] => id
                    [terms] => Array
                        (
                            [0] => 3
                        )

                )

            [1] => Array
                (
                    [taxonomy] => country
                    [field] => name
                    [terms] => Array
                        (
                            [0] => Россия
                        )

                )

            [2] => Array
                (
                )

            [3] => Array
                (
                )

        )

    [meta_query] => Array
        (
            [0] => Array
                (
                )

            [1] => Array
                (
                )

        )

    [orderby] => date
    [order] => DESC
)

2. request type 3 institutions in the country Russia, Moscow region, Moscow - there are results

Array
(
    [paged] => 0
    [posts_per_page] => 10
    [post_type] => institution
    [tax_query] => Array
        (
            [0] => Array
                (
                    [taxonomy] => institutions
                    [field] => id
                    [terms] => Array
                        (
                            [0] => 3
                        )

                )

            [1] => Array
                (
                    [taxonomy] => country
                    [field] => name
                    [terms] => Array
                        (
                            [0] => Россия
                        )

                )

            [2] => Array
                (
                    [taxonomy] => region
                    [field] => name
                    [terms] => Array
                        (
                            [0] => Московская область
                        )

                )

            [3] => Array
                (
                    [taxonomy] => city
                    [field] => name
                    [terms] => Array
                        (
                            [0] => Москва
                        )

                )

        )

    [meta_query] => Array
        (
            [0] => Array
                (
                )

            [1] => 
        )

    [orderby] => date
    [order] => DESC
)
 number of posts=10

That is, the results appeared when I narrowed down the search, how can this even be explained? Maybe taxonomies turned out to be mandatory when searching? And how to undo it, if so?