title: Karma tests randomly restart and "double" iframe in Edge
body: <p>I have a suite of Karma/Jasmine tests for my Angular 7 app.  All my tests pass in Chrome and Firefox, but when I run them in Edge it will run for a little bit and then sometimes it will randomly reload the page and start over, and sometimes it will load karma again into the iframe, thus "doubling" it.</p>
  
  <p>Here's what it looks like</p>
  
  <p><a href="https://i.stack.imgur.com/MXuzH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MXuzH.png" alt="double karma tests"></a></p>
  
  <p>However, when I click the "Debug" button it opens a new tab and all the tests run fine in there with no failures.</p>
  
  <p><a href="https://i.stack.imgur.com/JZCOR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JZCOR.png" alt="success debug karma tests"></a></p>
  
  <p>And here's what my console output looks like.  you can see it runs a few tests and then just restarts them</p>
  
  <p><a href="https://i.stack.imgur.com/DMekB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DMekB.png" alt="enter image description here"></a></p>
  
  <hr>
  
  <h2>What is going on here?</h2>
  
  <p>Why would it behave this way in Edge when there are no test failures?</p>