Instead default Astra Post's navigation use Previous Post Link function

functions.php

<?php
// Remove default Astra Post's Pagination.
remove_action( 'astra_entry_after', 'astra_single_post_navigation_markup' );

// Add Previous Post| Next Post Link for Post's Pagination.
add_action( 'astra_entry_after', 'astra_single_post_custom_navigation_markup' );

function astra_single_post_custom_navigation_markup() {

	$single_post_navigation_enabled = apply_filters( 'astra_single_post_navigation_enabled', true );

	if ( is_single() && $single_post_navigation_enabled ) {
		previous_post_link( '<div class="nav-previous"><span class="prev" title="' . esc_attr__( 'Previous', 'astra' ) . '">%link</span></div>', '%title' );
		next_post_link( '<div class="nav-next"><span class="next" title="' . esc_attr__( 'Next', 'astra' ) . '">%link</span></div>', '%title' );
	}
}

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