Bootstrap .justify-content-center not centering applied divs - html

Question

I have tried to place a search form into 2 parent divs. Whether I try the align or justify utility neither of them are able to center the search bar in the middle of the page, where I want it.
<div class="col">
<div class"container-fluid justify-content-center" id="searchform">
<form class="form-floating form-control-sm" id="form">
<div class="row " id="div_main">
<div class="col-auto " id="div_Location">
<label for="Location">Hunt Location</label><br>
<select name="cars" id="Location">
<option value="Gauteng">Gauteng</option>
<option value="Western Cape">Western Cape</option>
<option value="Northern Cape">Northern Cape</option>
<option value="North West">North West</option>
<option value="Limpopo">Limpopo</option>
<option value="Free State">Free State</option>
<option value="Mpumalanga">Mpumalanga</option>
<option value="Eastern cape">Eastern Cape</option>
<option value="Kwa-zulu Natal">kwa-zulu Natal</option>
</select>
</div>
<div class="col-auto" id="div_Animal">
<label for="Animal">Animal</label><br>
<select name="Animals" id="Animal">
<option value="" id="ListAnimal"></option>
</select>
</div>
<div class="col-auto" id="div_Check-in">
<label for="Check-in">Check-in</label>
<input type="date" class="form-control" id="Check-in" placeholder="Check-in" value="">
</div>
<div class="col-auto" id="div_Check-out">
<label for="floatingInputValue">Check-out</label>
<input type="date" class="form-control" id="Check-out" placeholder="Check-out" value="">
</div>
<div class="col-auto" id="div_Hunters">
<label for="Hunters">Hunters</label>
<input type="number" class="form-control" id="Hunters" placeholder="5" value="">
</div>
<div class="col-auto">
<button type="button" class="btn btn-dark d-iline" id="searchbutton"><img src="img/search.png"></img></button>
</div>
</div>
</form>
</div>
</div>

Answer 1

The default behavior of col is to take up 100% of the available space, so justify-content-center won't have any meaningful effect as the column is already at a width of 100% and cannot be centered relative to the parent container.
If we clean up your code the results you expect can be achieved fairly easily (Note: You will need to run this snippet full screen to see it centered).
<div class="container-fluid">
<div class="row justify-content-center">
<div class="col-auto" id="search-form">
<form class="form-floating form-control-sm" id="form">
<div class="form-row" id="div_main">
<div class="col-auto" id="div_Location">
<label for="Location">Hunt Location</label><br>
<select name="cars" id="Location" class="custom-select">
<option value="Gauteng">Gauteng</option>
<option value="Western Cape">Western Cape</option>
<option value="Northern Cape">Northern Cape</option>
<option value="North West">North West</option>
<option value="Limpopo">Limpopo</option>
<option value="Free State">Free State</option>
<option value="Mpumalanga">Mpumalanga</option>
<option value="Eastern cape">Eastern Cape</option>
<option value="Kwa-zulu Natal">kwa-zulu Natal</option>
</select>
</div>
<div class="col-auto" id="div_Animal">
<label for="Animal">Animal</label><br>
<select name="Animals" id="Animal" class="custom-select">
<option value="" id="ListAnimal"></option>
</select>
</div>
<div class="col-auto" id="div_Check-in">
<label for="Check-in">Check-in</label>
<input type="date" class="form-control" id="Check-in" placeholder="Check-in" value="">
</div>
<div class="col-auto" id="div_Check-out">
<label for="floatingInputValue">Check-out</label>
<input type="date" class="form-control" id="Check-out" placeholder="Check-out" value="">
</div>
<div class="col-auto" id="div_Hunters">
<label for="Hunters">Hunters</label>
<input type="number" class="form-control" id="Hunters" placeholder="5" value="">
</div>
<div class="col-auto align-self-end">
<button type="button" class="btn btn-dark" id="searchbutton">Search</button>
</div>
</div>
</form>
</div>
</div>
</div>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap#4.6.0/dist/css/bootstrap.min.css" integrity="sha384-B0vP5xmATw1+K9KRQjQERJvTumQW0nPEzvF6L/Z6nronJ3oUOFUFpCjEUQouq2+l" crossorigin="anonymous">
First I've applied the correct Grid components of container-fluid and row to make sure that everything is lined up as one would expect within Bootstrap. You may have omitted that for brevity but I wanted to make sure it was shown.
Changing .col to .col-auto will allow the form's parent element to take up only as much width as needed, which will allow justify-content-center to center the column when applied to row.
If you don't want to apply that class to the row wrapper, you can apply mx-auto to the col-auto wrapper.
A couple of house-keeping notes:
As isherwood stated in the comments, your original use of an additional container element is not needed, and is in fact frowned upon as it can result in unexpected issues.
The <img> tag is self-closing, meaning you should format it either as <img src="..." /> or without the self-closing slash. </img> does not exist.