XSD schema not validating in basex

I am tasked with adding type="DeptType" to an xsd file and validating it in basex against an xml document. I have validated both in notepad++ but I get an error in basex when trying to validate.

XSD

<?xml version="1.0"?>
<xs:schema
    xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="root">
    <xs:complexType>
        <xs:sequence>
            <xs:element name="dept" type="DeptType" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:simpleContent>
                        <xs:extension base="xs:string">
                            <xs:attribute name="id" type="xs:string" />
                        </xs:extension>
                     </xs:simpleContent>
                  </xs:complexType>
            </xs:element>
            <xs:element name="staff" type="StaffType" maxOccurs="unbounded" />
        </xs:sequence>
    </xs:complexType>
    <xs:key name="deptKey">
        <xs:selector xpath="dept"/>
        <xs:field xpath="@id"/>
    </xs:key>
    <xs:key name="staffKey">
        <xs:selector xpath="staff"/>
        <xs:field xpath="@id"/>
    </xs:key>
    <!-- keyref does not work with simpleContent -->
    <xs:keyref name="staffdeptref" refer="deptKey">
        <xs:selector xpath="staff"/>
        <xs:field xpath="@dept"/>
    </xs:keyref>
</xs:element>
<xs:complexType name="StaffType">
    <xs:choice>
        <xs:element name="staff" type="StaffType" maxOccurs="unbounded" />
        <xs:element name="name" type="xs:string"/>
    </xs:choice>
    <xs:attribute name="dept"/>
    <xs:attribute name="id"/>
</xs:complexType>
</xs:schema>

xml

<?xml version="1.0" ?>
<root  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="test.xsd">
    <dept id="i1"><name>it</name></dept>
    <dept id="i2"><name>law</name></dept>
    <staff id="i2"><name>steve</name></staff>
    <staff id="i3" dept="i2"><name>jerry</name></staff>
</root>

basex validation validate:xsd("doc-4xsd.xml")

The error I get is enter image description here

I think it's because of this part:

<xs:element name="dept" type="DeptType" maxOccurs="unbounded">
    <xs:complexType>

Since the complexType is defined within the element, you shouldn't specify the type attribute. I think the type attribute is just for referencing types elsewhere in the schema. So it's either:

<xs:element name="dept" maxOccurs="unbounded">
    <xs:complexType>

or

<xs:element name="dept" type="DeptType" maxOccurs="unbounded"/>

<xs:complexType name="DeptType">

but not both.