bad arg and connection errors using Netconf-Yang on IOS-XE

Question

I'm working Netconf-Yang for the first time on an IOS-XE device (Cat 9k, 16.8.1r) and I'm sending the following XML block to change an interface description.

I'm using ansible netconf_config with these parameters:

- name: netconf playbook
  hosts: switch1
  vars:
    ansible_connection: netconf
    ansible_port: 830
    outfile: yang-config.xml

  tasks:
    - name: Changing interfaces description
      netconf_config:
        lock: if-supported
        error_option: rollback-on-error
        default_operation: "merge"
        commit: yes
        content: "{{ lookup('file', outfile) }}"
      register: result

    - debug:
        var: result


Contents of outfile: >>>


<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
    <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
        <interface>
            <name>GigabitEthernet1/1/1</name>
            <description>netconf-test1</description>
            <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type>
        </interface>
    </interfaces>
</config>

I then get the following errors. I've ruled out authentication problems. It's not the username or password, it's not an ACL on the switch. It has to be something wrong with the model, somehow. I've validated it with pyang2dsdl but it just tells me "config" should be "data".

TASK [Changing interfaces description] *********************************************************************************************************************************************************
The full traceback is:
  File "/tmp/ansible_netconf_config_payload_jx0san85/ansible_netconf_config_payload.zip/ansible/modules/network/netconf/netconf_config.py", line 401, in main
  File "/tmp/ansible_netconf_config_payload_jx0san85/ansible_netconf_config_payload.zip/ansible/module_utils/connection.py", line 185, in __rpc__
    raise ConnectionError(to_text(msg, errors='surrogate_then_replace'), code=code)
fatal: [switch1]: FAILED! => changed=false 
  invocation:
    module_args:
      backup: false
      backup_options: null
      commit: true
      confirm: 0
      confirm_commit: false
      content: |-
        <config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
            <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
                <interface>
                    <name>GigabitEthernet1/1/1</name>
                    <description>netconf-test1</description>
                    <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type>
                </interface>
            </interfaces>
        </config>
      default_operation: merge
      delete: false
      error_option: rollback-on-error
      format: xml
      host: null
      hostkey_verify: true
      lock: always
      look_for_keys: true
      password: null
      port: 830
      save: false
      source_datastore: null
      src: null
      ssh_keyfile: null
      target: auto
      timeout: 10
      username: null
      validate: false
  msg: |-
    error: /oc-stp:stp/rapid-pvst/vlan: badarg
    error: /oc-sys:system/ntp/config/ntp-source-interface: badarg
    error: /oc-sys:system/aaa/authentication/config/authentication-method: {case_clause,<<"tacgroup">>}

I haven't been able to find anything about this error. Thanks for your help.