title: Sessions are not working when the site is called by an iframe
body: <p>I have a first site <a href="https://www.mydomain1.com" rel="nofollow noreferrer">https://www.mydomain1.com</a> in which I use PHP sessions. No problem, everything works fine, when I go from page to page, I can access my session variables.</p>
  <p>I have a second site <a href="https://www.mydomain1.com" rel="nofollow noreferrer">https://www.mydomain1.com</a> in which I display part of my 1st site via an iframe:</p>
  <pre><code>&lt;iframe src = &quot;https://www.mydomain1.com&quot; width = &quot;100%&quot; frameborder = &quot;0&quot; style = &quot;border: 0&quot; allowfullscreen = &quot;allowfullscreen&quot; id = &quot;frameLeonard&quot;&gt; &lt;/iframe&gt;
  </code></pre>
  <p>And there strangely, the session variables are no longer recognized. I'm not even trying to get my 1st site to access the session variables from the 2nd site (that's not the goal and it's normal that it doesn't work) but just run the 2nd site inside the 1st site.</p>
  <p>Strangely, it was still working a year ago.
  Has there been any upgrade that would explain the problem?</p>
  <p>Thank you in advance for your lights !</p>