title: Testcafe tests ran by automation servers fail randomly
body: <p>This is inconsistent behavior, I am getting random results with both Jenkins and GitLab-runner. When running the failing tests on the same build machine,  everything goes well. (e.g. the tests that failed when ran by the automation server, pass when ran manually - using <em>test.only</em>)</p>
  
  <p>Tried mostly headless with Firefox and Chrome but the same randomness happens with full UI as well.</p>
  
  <p>First off, I thought there was a resource problem on the build machine because of concurrent tasks, but I ruled this off by scheduling a nightly build. Moreover, I even reduced the speed to 0.8.</p>
  
  <p>Has anyone else encountered this behavior? Any hint will be greatly appreciated.</p>