title: What could cause a correlation cookie to not be returned on specific devices
body: <p>We have some users who cannot connect to our platform via Google. When this happens, it's always for a specific device, but with the information we have so far, it's not all the same device kind (to be confirmed).</p>
  
  <p>We're using ASP.NET Core (and Identity Server 4).</p>
  
  <p>The error on our side is that upon returning from the oauth flow, the correlation cookie set by ASP.NET identity is gone. We have verified that it's well set at the beginning, and is valid. It's not an issue about data protection (we do have this in place). We can reproduce on two iPads with iOS 12, no matter which account we try to connect with. All those accounts can connect on other devices, including iPads with iOS 13.</p>
  
  <p>So we're trying to isolate what could make those specific devices fail. Also, it seems this only started to happen recently, and we can't identify what change could have triggered this on our side.</p>
  
  <h3>Update 1</h3>
  
  <p>Updating an iPad from iOS 12 to iOS 13 solves the issue.</p>