How is "unique" on fields intended to work?

[bhofstaetter]

Hi, according to the documentation, you can assign the property “unique: true” to a field so that every document in the collection must have a unique value for this field. Do I understand this correctly? If so, have I configured it incorrectly or does this feature not work?

        {
            name: 'companyNumber',
            label: t('companyNumber'),
            type: 'text',
            required: true,
            unique: true,
            // validate: validateCompanyNumber,
            access: {
                create: superAdminsFieldAccess,
                update: superAdminsFieldAccess,
            },
        },