When I insert a drop-down list and a text box, the CSS style is not on the same line

this problem is identified precisely when inserting a drop-down list + text field

my code

<main>
<div class="container-fluid">
<section class="card card-cascade narrower mb-5">
<div class="row">
<div class="col-12">
<div class="view view-cascade py-3 gradient-card-header info-color-dark">
<h5 class="mb-0">Head</h5>
</div>
<form asp-action="Create" method="post">
<div class="card-body">
<div class="form-row">
<div class="form-group col-10">
<div class="md-form">
<select class="mdb-select">
<option value="" disabled selected>Choose your option</option>
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
</select>
<label>Example label</label>
</div>
</div>
<div class="form-group col-2">
<div class="md-form">
<div class="md-form">
<input type="text" id="form1" class="form-control">
<label for="form1" >Example label</label>
</div>
</div>
</div>
</div>
</div>
</form>
</div>
</div>
</section>
</div>
</main>