Dynamic Data Target on Modal PHP - php

Question

I am looping a dynamic PHP value and also a button that is linked with a modal form.
The problem is that im currently setting the data-target to one of the dynamic values being looped but it never gets to work.
This is the PHP+HTML code being looped:
while($row = mysqli_fetch_assoc($seleccionar_requerimientos)){
$req_id = $row['req_id'];
?>
<tr>
<td><?php echo "{$req_id}" ?></td>
<!-- Here we place the data-target to dynamic value -->
<td><p data-placement="top" data-toggle="tooltip" title="Editar"><button class="btn btn-primary btn-xs" data-title="Edit" data-toggle="modal" **data-target="#<?php echo $req_id; ?>" ><span class="fas fa-edit"></span></button></p></td>
<!-- Here we set the dynamic ID linked to previous trigger -->
<div class="modal fade" id="<?php echo $req_id; ?>" tabindex="-1" role="dialog" aria-labelledby="edit" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true"><span class="glyphicon glyphicon-remove" aria-hidden="true"></span></button>
<h4 class="modal-title custom_align" id="Heading">Editar Requerimiento</h4>
</div>
<div class="modal-body">
<div class="form-group">
<textarea rows="2" class="form-control" placeholder="<?php echo $req_desc_corta; ?>"></textarea>
</div>
</div>
<div class="modal-footer ">
<button type="button" class="btn btn-warning btn-lg" style="width: 100%;"><span class="fas fa-wrench"></span> Actualizar</button>
</div>
</div>
</div>
</div>
<?php } ?>
Where am I wrong? I can see on the site source code that both values are currently properly set but modal still not showing.
If values on both data-target and ID are dynamic, they are properly displayed on site source code but the modal never triggers.
If values are manually writen, the modal pops up correctly which confirms modal code is working, however since its not a dynamic value it opens up the same form for every looped item, which is the reason to write a dynamic value on them.
This is the HTML output I get on the source code whiledisplaying dynamic values:
<!-- Echo en bucle de los botones de editar el requerimiento -->
<td><p data-placement="top" data-toggle="tooltip" title="Editar"><button class="btn btn-primary btn-xs" data-title="Edit" data-toggle="modal" data-target="#9" ><span class="fas fa-edit"></span></button></p></td>
<!-- Pop Up con el form de editar el requerimiento -->
<div class="modal fade" id="9" tabindex="-1" role="dialog" aria-labelledby="edit" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true"><span class="glyphicon glyphicon-remove" aria-hidden="true"></span></button>
<h4 class="modal-title custom_align" id="Heading">Editar Requerimiento</h4>
</div>
<div class="modal-body">
<div class="form-group">
<textarea rows="2" class="form-control" placeholder="dsfgdfg"></textarea>
</div>
</div>
<div class="modal-footer ">
<button type="button" class="btn btn-warning btn-lg" style="width: 100%;"><span class="fas fa-wrench"></span> Actualizar</button>
</div>
</div>
</div>
</div>
Weirdly, if I change
data-target="#<?php echo $req_id; ?>"
To
data-target="#9"
And I also change
<div class="modal fade" id="<?php echo $req_id; ?>" tabindex="-1" role="dialog" aria-labelledby="edit" aria-hidden="true">
To
<div class="modal fade" id="9" tabindex="-1" role="dialog" aria-labelledby="edit" aria-hidden="true">
Then it works (with static values)

Answer 1

I think using only numbers for the id attribute is a bad idea. Please, use some string before the number. From https://www.w3schools.com/tags/att_global_id.asp :
Must contain at least one character

Answer 2

Is it possible that your code is generating duplicate values for $req_id?
If the code works when you manually put the IDs in place then the problem is likely the Ids and there aren't many ways this could be wrong. Either there are duplicate IDs or there's some other issue with the way they are being output. Can you add the source code of the whole page? Does you console warn you about duplicated IDs?