Multi-App Kiosk mode provisioning failure code '0xC00CE223' - kiosk-mode

Question

I'm trying to put in place a kiosk on a Surface Go using the following AssignedAccess.xml file in my provisioning package:
<?xml version="1.0" encoding="utf-8" ?>
<AssignedAccessConfiguration
xmlns="https://schemas.microsoft.com/AssignedAccess/2017/config"
xmlns:r1809="https://schemas.microsoft.com/AssignedAccess/201810/config"
>
<Profiles>
<Profile Id="{f46cfb9f-044f-4d96-bb33-ea1c1c18a354}">
<AllAppsList>
<AllowedApps>
<App AppUserModelId="Microsoft.Windows.Explorer" r1809:AutoLaunch="true" />
<App AppUserModelId="Microsoft.WindowsCalculator_8wekyb3d8bbwe!App" />
<App DesktopAppPath="C:\Program Files\SumatraPDF\SumatraPDF.exe" />
</AllowedApps>
</AllAppsList>
<r1809:FileExplorerNamespaceRestrictions>
<r1809:AllowedNamespace Name="Downloads" />
</r1809:FileExplorerNamespaceRestrictions>
<StartLayout>
<![CDATA[<LayoutModificationTemplate xmlns:defaultlayout="http://schemas.microsoft.com/Start/2014/FullDefaultLayout" xmlns:start="http://schemas.microsoft.com/Start/2014/StartLayout" Version="1" xmlns="http://schemas.microsoft.com/Start/2014/LayoutModification">
<LayoutOptions StartTileGroupCellWidth="6" />
<DefaultLayoutOverride>
<StartLayoutCollection>
<defaultlayout:StartLayout GroupCellWidth="6">
<start:Group Name="Apps">
<start:Tile Size="4x2" Column="0" Row="2" AppUserModelID="Microsoft.WindowsCalculator_8wekyb3d8bbwe!App" />
<start:DesktopApplicationTile Size="2x2" Column="0" Row="0" DesktopApplicationLinkPath="%APPDATA%\Microsoft\Windows\Start Menu\Programs\SumatraPDF.lnk" />
<start:DesktopApplicationTile Size="2x2" Column="2" Row="0" DesktopApplicationLinkPath="%APPDATA%\Microsoft\Windows\Start Menu\Programs\System Tools\File Explorer.lnk" />
</start:Group>
</defaultlayout:StartLayout>
</StartLayoutCollection>
</DefaultLayoutOverride>
</LayoutModificationTemplate>
]]>
</StartLayout>
<Taskbar ShowTaskbar="false" />
</Profile>
</Profiles>
<Configs>
<Config>
<Account>CouncilKiosk</Account>
<DefaultProfile Id="{f46cfb9f-044f-4d96-bb33-ea1c1c18a354}"/>
</Config>
</Configs>
</AssignedAccessConfiguration>
I took a look at the logs and the consensus seems to be this error code '0xC00CE223'. According to my research this is telling me that "Validate failed because the document does not contain exactly one root node." (XML DOM Error Messages Doc) I'm not sure where this is going wrong.
The provisioning package is also setting 2 user accounts (local admin and local user), hiding OOBE, enabling tablet mode as default, and running a provisioning command script that installs a single application and sets registry keys necessary for autologin.
UPDATE: I re-imaged the Surface Go with Windows 10 Pro and it still fails. But now I get an error '0x8000FFFF' which appears to be related to windows update and the windows store. I only have 1 USB port on this thing so it isn't connected to the internet at this time.
UPDATE 2: I re-imaged with a more up to date ISO of 10 Pro and I'm back to the original errors listed in the above post. I have updated the XML file and changed the tag as well as the xmlns from rs5 to r1809. I am not seeing any changes and this continues to be a frustrating problem to have.

Answer 1

Test to change this:
https://schemas.microsoft.com/AssignedAccess/2017/config
to the following:
http://schemas.microsoft.com/AssignedAccess/2017/config