After uninstalling the shield, config should be deleted.

I have the exact same problem. Caught the eye in 💬 Undefined constant "Drupal\node\Entity\DRUPAL_OPTIONAL" Active
https://www.drupal.org/project/shield/issues/3304657#comment-15694393 💬 Undefined constant "Drupal\node\Entity\DRUPAL_OPTIONAL" Active

Can confirm that there is no shield.setting entry in the config table after uninstalling, but there is still the described error which discards the whole instance and makes it unusable. As soon as the module is reactivated “drush en shield”, the page works again. In the logs it simply says Access denied for each path you have selected, otherwise no error or message.

Only affects the Shield module, other modules can be installed and uninstalled without any problems. But it only happened to me after I had installed a patch (but not anymore), see link. any ideas?

Strangely enough, importing a DB backup doesn't help either...

Tried with full backup, it's working again now.

Can anyone tell me if this is specific to Shield or a general phenomenon or what could be the cause? Depending on that, this issue can be treated further or analyzed somewhere else.

This borked multiple Drupal 11 websites because it doesn't work causing database corruption if used.

Not uninstalling it causes what is described here..

This is a black flag on this module.. don't use.