This only occurs when using Symfony stack, with legacy fallback.
In a legacy module, when you set a session variable and then perform a redirection (e.g. using $Module->redirectTo( '/' )) to a page managed by Symfony stack, created session will be lost during the redirection process.
Steps to reproduce
- Create a legacy module with the following code:
- Create a custom symfony controller with a /my_custom_controller_uri route, and ensure you dump foo session variable:
- Access to your legacy module URL, you'll be redirected to your custom controller and foo session variable will be null