Not able to get my custom search result using meta_query and tax_query together?

I created a custom search where i am able to show the Fields (ACF fields) and also Taxonomies. But while I am searching by taking the combination of both Taxonomies and meta fields, i am not getting the results. It is giving the results if i will search either Taxonomies or meta fields. How to make both conditions work together?

This is my code where i mentioned both meta_query and tax_query:-

?php
if($_POST){
    $_speciality = $_POST['speciality'] != '' ? $_POST['speciality'] : '';
    $_students_last_name = $_POST['students_last_name'] != '' ? $_POST['students_last_name'] : '';

    if($_speciality!=" "){
        $param1 = array(
            'key' = 'speciality',
            'compare' = '=',
            'value' = $_speciality
        );
    } else{
        $param1 = "";
    }

    if($_students_last_name!=" "){
        $param2=array(
            'key'       = 'students_last_name',
            'compare'   = 'LIKE',
            'value'     = $_students_last_name
        );
    } else{
        $param2="";
    }

    $args = array(
        'post_type' = 'students',
        'orderby'   = 'date',
        'order'     = 'DESC',
        'tax_query' = array(
            array(
                'taxonomy'  = 'Music',
                'field'     = 'slug',
                'terms'     = $param1
            )
        ),
        'meta_query' = array(
            'relation' = 'AND',
            $param2
        ),      
    );

} else {
    $args = array(
        'post_type' = 'students',
        'orderby' = 'date',
        'order' = 'DESC'
    );
}

$the_query = new WP_Query( $args );