Always reproduced:

```
milovidov-desktop :) create table table_map (a Map(String, String), b String) engine = MergeTree() order by a;

CREATE TABLE table_map
(
    `a` Map(String, String),
    `b` String
)
ENGINE = MergeTree
ORDER BY a

Query id: 8f8120c1-c165-452a-815f-2bcae3957e2a

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) SELECT b FROM table_map WHERE a = map('name', NULL, '', NULL)

SELECT b
FROM table_map
WHERE a = {'name', NULL, '', NULL}
```
auto wrapper = prepareRemoveNullable(from_nested, to_nested, skip_not_null_check);
        if (!from_low_cardinality && !to_low_cardinality)
            return wrapper;
        return [wrapper, from_low_cardinality, to_low_cardinality, skip_not_null_check]
                (ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, const ColumnNullable * nullable_source, size_t input_rows_count) -> ColumnPtr
        {
            ColumnsWithTypeAndName args = {arguments[0]};
            auto & arg = args.front();
            auto res_type = result_type;
            ColumnPtr converted_column;
            ColumnPtr res_indexes;
            
            bool src_converted_to_full_column = false;
            {
                auto tmp_rows_count = input_rows_count;
                if (to_low_cardinality)
                    res_type = to_low_cardinality->getDictionaryType();
                if (from_low_cardinality)
                {
                    const auto * col_low_cardinality = typeid_cast<const ColumnLowCardinality *>(arguments[0].column.get());
                    if (skip_not_null_check && col_low_cardinality->containsNull())
                        throw Exception{"Cannot convert NULL value to non-Nullable type",
                                        ErrorCodes::CANNOT_INSERT_NULL_IN_ORDINARY_COLUMN};
                    arg.column = col_low_cardinality->getDictionary().getNestedColumn();
                    arg.type = from_low_cardinality->getDictionaryType();
                    
                    src_converted_to_full_column = !removeNullable(arg.type)->equals(*removeNullable(res_type));
                    if (src_converted_to_full_column)
                        arg.column = arg.column->index(col_low_cardinality->getIndexes(), 0);
                    else