I have a tab list panel and the last tab uses the full calendar

And there is this problem, when switching to the tab, the css of the calendar is not loading, but if I switch to another month of the calendar itself, the css starts working

My calendar version is 5.7.2, I did not observe such a problem for version 3, what could be the problem?

var data = [];

$(document).ready(function() {
    var calendarEl = document.getElementById('calendar');

    var calendar = new FullCalendar.Calendar(calendarEl, {
        initialView: 'dayGridMonth',
        headerToolbar: {
            left: 'prev',
            center: 'title',
            right: 'next'
        },
        editable: false,
        contentHeight: 705,
        events: data
    });

    calendar.render();
});

html, body {
  margin: 0;
  padding: 0;
  font-family: "Lucida Grande",Helvetica,Arial,Verdana,sans-serif;
  font-size: 14px;
}

#calendar {
  max-width: 900px;
  margin: 20px auto;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-eOJMYsd53ii+scO/bJGFsiCZc+5NDVN2yr8+0RDqr0Ql0h+rP48ckxlpbzKgwra6" crossorigin="anonymous">

<link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.10.0/css/all.css" integrity="sha384-AYmEC3Yw5cVb3ZcuHtOA93w35dYTsvhLPVnYs9eStHfGJvOvKxVfELGroGkvsg+p" crossorigin="anonymous" />

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/main.min.css" />

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.11.1/moment.min.js" integrity="sha512-TAVtO5mj3yhqvqWq539ELZe1kdI+ggl2XkVNJ7h33EeYK03qTyiKPbTu2DrrsuWlggnvCr3+A29goA7y0aZSFg==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

<script src="https://unpkg.com/[email protected]/main.js"></script>

<script src="https://code.jquery.com/ui/1.11.3/jquery-ui.min.js"></script>

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js" integrity="sha384-ygbV9kiqUc6oa4msXn9868pTtWMgiQaeYH7/t7LECLbyPA2x65Kgf80OJFdroafW" crossorigin="anonymous"></script>

<nav>
  <div class="nav nav-tabs" id="nav-tab" role="tablist">
    <button class="nav-link active" id="nav-home-tab" data-bs-toggle="tab" data-bs-target="#nav-home" type="button" role="tab" aria-controls="nav-home" aria-selected="true">
                                Home
                            </button>
    <button class="nav-link" id="nav-profile-tab" data-bs-toggle="tab" data-bs-target="#nav-profile" type="button" role="tab" aria-controls="nav-profile" aria-selected="false">
                                Profile
                            </button>
    <button class="nav-link" id="nav-calendar-tab" data-bs-toggle="tab" data-bs-target="#nav-calendar" type="button" role="tab" aria-controls="nav-calendar" aria-selected="false">
                                Calendar
                            </button>
  </div>
</nav>
<div class="tab-content" id="nav-tabContent">
  <div class="tab-pane fade show active" id="nav-home" role="tabpanel" aria-labelledby="nav-home-tab">Home</div>
  <div class="tab-pane fade" id="nav-profile" role="tabpanel" aria-labelledby="nav-profile-tab">Profile</div>
  <div class="tab-pane fade" id="nav-calendar" role="tabpanel" aria-labelledby="nav-calendar-tab">
    <div id="calendar"></div>
  </div>
</div>