I have a custom module for an online shop. Module's controller gets a product id which is sent by the user through a query string and puts it into the session. That is crucial for the shopping cart functionality.
Things are that, after clearing the cache, everything is ok, but after a few minutes/requests, the requests stop entering the controller. It seems like the response has been cached, even if:
- I have disabled the caches at admin/config/development/performance,
- I return '#cache' => ['max-age => 0] within the render array returned by the controller and
- all responses come with the header "x-drupal-cache-max-age: 0 (Uncacheable)".
I also noticed that these errors usually come with the following apache error:
AH01070: Error parsing script headers