A problem with Select 2

I have a problem with select2.
Has you can see in my image, it’s seems like there is 2 select (but I have only 1 on my code).
Here is my code:

{% extends 'base.html.twig' %}

{% block title %}Mini-stage{% endblock %}

{% block main %}
{# Inclure les fichiers CSS et JS de Select2 #}
<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/select2.min.css" rel="stylesheet" />
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/select2.min.js"></script>

    <section class="job_section layout_padding">
        <div class="container">
            <div class="row">
                <div class="col-md-10 col-lg-8 mx-auto">
                    <div class="profile-container">
                        <!-- Formulaire pour les Infos Établissement -->
                        <div class="tab-content" id="classe-info">
                            <div class="form-container">
                                <h2>Informations de la classe</h2>
                                <form action="" method="post">
                                    <div class="form-group">
                                        <label for="diplome">Sélection de la filière:</label> 
                                            <select id="diplome" class="diplomes">
                                                <option value="">{{unType.nom}} {{unDiplome.nom}}</option>
                                                {% for diplome in diplomes %}
                                                    <option value={{diplome.idDip}}>{{diplome.nomType}} {{diplome.nomDip}}</option>
                                                {% endfor %}

                                    <div class="form-group">
                                        <label for="stage-description">Description :</label>
                                        <textarea id="stage-description" name="stage-description" rows="4" cols="50"></textarea>

                                    <div class="form-group">
                                        <button type="submit" onclick="showTab('classe-list')">Enregistrer</button>


{# Script JavaScript pour initialiser Select2 #}
    $(document).ready(function() {

{% endblock %}