The solution is not to add the default trust level 2 group as category moderators. The system does not recognize that group and therefore a new group must be created. Solution by @iStxrm.
「いいね！」 1
The trust level groups cannot be used for category moderation. You need to use custom groups that you create for category moderation. Renaming a trust level group cannot be used as a way of getting around this issue.
「いいね！」 2