Recently, I was building a custom Drupal form that used dependency injection and included an ajax submit handler. While testing the form, on the initial page load, the form submitted just fine using ajax. However, when the user used another ajax handler on the same form, all of the injected services were set to `NULL`.
It turns out that I had my services set to be private $myService; , which were not able to be serialized in the form. Changing these to protected $myService; solved the issue.
Thanks for the assist: https://drupal.stackexchange.com/questions/287289/form-state-cache-brea…