I'm encountering an issue with Bootstrap 4 collapse. Everything works as expected unless I add the "d-flex" class to my form tag.
When I include the "d-flex" class, the form is initially displayed. Upon clicking #reservas_button, the form toggles from hidden to shown and back again.
<!--reservas-->
<div id="reservas" class="container d-flex flex-column flex-sm-row align-items-center align-items-sm-start">
<h2 id="reservas_button" data-toggle="collapse" href="#reservas_form">RESERVAS</h2>
<form id="reservas_form" class="collapse d-flex flex-wrap">
...
</div>
<!--/reservas-->