FancyBox breaks the php. How to decide?

Question

PHP

In general, I take data from the MySQL database. I'm trying to display them in a structured way through a loop in php, but at the moments where I use FancyBox, the loop breaks (the variable is always equal to the initial value of the loop). Here is a piece of code:

<?php
          for($i=0; $i<3; $i++)
          {
            echo '
            <div class="col-md-4 EinWare">
                 			<h3>'.$all_products[$i]['title'].'</h3>
                 			<a class="Produktbeschreibung" href="#produkte1"><img src="/image/Katalog/'.$all_products[$i]['image'].'" class="Einzug3 imaginator2"></a>
                 			<p>'.$all_products[$i]['description'].'</p>
                 			<p class="price">Цена: '.$all_products[$i]['price'].' рублей</p>
                 			<a class="Produktbeschreibung" href="#produkte1">Подробнее</a>
              <form class="variants" action="#">
                <input type="submit" class="buy btn btn-custom" value="Купить" data-result-text="Куплено"/>
              </form>
            			</div>
            			<div style="display: none;">//в этом блоке
              <div id="produkte1" class="container-fluid">
                <h3>'.$all_products[$i]['title'].$i.'</h3>
                <div class="col-md-3">
                  <img src="/image/Katalog/'.$all_products[$i]['image'].'" class="Einzug3 imaginator2">
                </div>
                <div class="col-md-6">
                  <p>'.$all_products[$i]['full_description'].'</p>
</p>
                  <p>'.$all_products[$i]['description'].'</p>
                     			<p class="price">Цена: '.$all_products[$i]['price'].' рублей</p>
                  <form class="variants" action="#">
                    <input type="submit" class="buy btn btn-custom" value="Купить" data-result-text="Куплено"/>
                  </form>
                </div>
              </div>
            			</div>';
            			}
            			?>

Oh yes, I almost forgot .. I have 2 JQuery libraries connected, one for Bootstrap, the other for FancyBox. But I checked, if one is turned off, everything also remains.
PS
all decided. the problem was that the id for calling FancyBox was the same. I added a variable to id and it began to change in the loop. Problem solved. Here are the changed lines of code

<a class="Produktbeschreibung" href="#produkte'.$i.'"><img src="/image/Katalog/'.$all_products[$i]['image'].'" class="Einzug3 imaginator2"></a>
...
<a class="Produktbeschreibung" href="#produkte'.$i.'">Подробнее</a>
...
<div id="produkte'.$i.'" class="container-fluid">

Answer 1

You have some kind of mess both in your head and in your code.
Fancybox (if you are talking about a library that allows you to "beautifully" enlarge images on a page) does not affect php in any way, because fancybox runs in the browser, and php runs on the server.
And it is better to write the code in such a way that it is easier to read:

<?php for($i=0; $i<3; $i++) { ?>
    <div>
        ... 
        <?= $all_products[$i]['title'] ?>
        ...
    </div>
<?php } ?>