Cards with read-more in bootstrap

I am using the following code to achieve a three-column design with a read more button. I changed the columns to display:flex to make them the same height. It looks fine when in default state. When you open a read-more option though, the other buttons shift too. Is there a possibility to prevent the buttons from shifting?

   <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
   
   <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
   
   <!-- make cards same height -->
    <section id="cards" class="py-5 bg-white">
      <div class="container">
        <div class="row">
          <!-- diplay cards as flexbox, direction column and space between -->
          <div class="col-12 col-sm-4 d-flex flex-column justify-content-between">
            <!-- wrap text in a div -->
            <div>
              <h1>Shootings</h1>
              <p>Willkommen bei den ganzen tollen Elementen</p>
              <div class="collapse mb-3" id="collapseWidthExample1">
                This is some placeholder content for a horizontal collapse. It's hidden by default and shown when triggered.
              </div>
            </div>
            <!-- wrap button in a div -->
            <div>
              <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#collapseWidthExample1" aria-expanded="false" aria-controls="collapseWidthExample">Read more</button>
            </div>
          </div>
          <div class="col-12 col-sm-4 d-flex flex-column justify-content-between">
            <div>
              <h1>Shootings</h1>
              <p>Willkommen bei den ganzen tollen Elementen. Willkommen bei den ganzen tollen Elementen.</p>
              <div class="collapse mb-3" id="collapseWidthExample2">
                This is some placeholder content for a horizontal collapse. It's hidden by default and shown when triggered.
              </div>
            </div>
            <div>
              <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#collapseWidthExample2" aria-expanded="false" aria-controls="collapseWidthExample">Read more</button>
            </div>
          </div>
          <div class="col-12 col-sm-4 d-flex flex-column justify-content-between">
            <div>
              <h1>Shootings</h1>
              <p>Willkommen bei den ganzen tollen Elementen
              <div class="collapse mb-3" id="collapseWidthExample3">
                This is some placeholder content for a horizontal collapse. It's hidden by default and shown when triggered.
              </div>
              </p>
            </div>
            <div>
              <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#collapseWidthExample3" aria-expanded="false" aria-controls="collapseWidthExample">Read more</button>
            </div>
          </div>
        </div>
      </div>
    </section>