there are many xml(xx).xml in the temp directory

Maybe a MS bug

No one will know until someone who has the problem is able to identify the process that is creating/reading/deleting the files, and/or examines the content of the files to see what they contain.

As I commented on June-1, remove the asterisk from the filter.

Despite it's name, C:\Temp is not a well known temp folder unless a user has updated the TEMP or TMP environment variables. So it could be a permissions issue where the user is allowed to write to the folder but does not have delete access. Check the NTFS permissions on the folder. A procmon trace might also show if any other process was trying to read these files and also delete them.

I found these files on my Win11 laptop. They are empty.

I can confirm that turning off Widgets stops those xml_file.xml files from being created.

And while they are zero length, there is an alternate data stream named StreamedFileState on them, but it's something in binary.

PS C:\Users\madne\AppData\Local\Temp> Get-Item .\xml_file.xml -stream *
PSPath        : Microsoft.PowerShell.Core\FileSystem::C:\Users\madne\AppData\Local\Temp\xml_file.xml::$DATA
PSParentPath  : Microsoft.PowerShell.Core\FileSystem::C:\Users\madne\AppData\Local\Temp
PSChildName   : xml_file.xml::$DATA
PSDrive       : C
PSProvider    : Microsoft.PowerShell.Core\FileSystem
PSIsContainer : False
FileName      : C:\Users\madne\AppData\Local\Temp\xml_file.xml
Stream        : :$DATA
Length        : 0
PSPath        : Microsoft.PowerShell.Core\FileSystem::C:\Users\madne\AppData\Local\Temp\xml_file.xml:StreamedFileState
PSParentPath  : Microsoft.PowerShell.Core\FileSystem::C:\Users\madne\AppData\Local\Temp
PSChildName   : xml_file.xml:StreamedFileState
PSDrive       : C
PSProvider    : Microsoft.PowerShell.Core\FileSystem
PSIsContainer : False
FileName      : C:\Users\madne\AppData\Local\Temp\xml_file.xml
Stream        : StreamedFileState
Length        : 32
PS C:\Users\madne\AppData\Local\Temp> Get-Item .\xml_file.xml | get-content -stream StreamedFileState
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PS C:\Users\madne\AppData\Local\Temp> Get-Item .\*.xml | get-content -stream StreamedFileState
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PS C:\Users\madne\AppData\Local\Temp>

I followed the instructions and watched as the XML files appeared in the TEMP directory. There was nothing in the Process Monitor. Not sure what I did wrong.