where is the 4th taxonomy terms? taxonomy terms is disaapearing in the loop

You skip to the else part in after the 4th run of your foreach. Put the $i++ at the end of the loop and your fine.

foreach( $tax_terms as $tax_term ) {
    if( $i <= 4 ) {
        echo '<td><a href="' . esc_attr( get_term_link( $tax_term, $taxonomy ) ) . '" title="' . sprintf( __( "Profilleri Görüntüle %s" ), $tax_term->name ) . '" ' . '>' . $tax_term->name . '</a></td>';
        echo ("\n"); 
    } else {       
        echo '</tr><tr>';
        $i = 0;
    }
    $i++;
}