[Powershell] [API] Delete endpoint by api fails with "invalid Operation"

[Update: found workaround]]

I changed the script that it will produce a batch file with curl and execute this. result is that the endpoints are removed as wished.

[Edited due adding full script]]

Dear Community,

I run in an issue I do not understand.

I wrote a powershell script which should delete endpoints in a specific group.

Enabling/disabling tamper works (non-destructive script testing), but when I execute the delete, it always fails with 

Invoke-RestMethod : {
"error": "BadRequest",
"correlationId": "d8889e3a-5914-4d68-bb5a-2765467c17d7",
"requestId": "c78db0c0-6bf7-40e5-968b-510cd7cb1d6f"
}
At line:3 char:13
+ $response = Invoke-RestMethod 'api-eu02.central.sophos.com/en ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-RestMethod], WebException
+ FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand

The used command:

Invoke-RestMethod 'api-eu02.central.sophos.com/.../xxxxxx-xxx-45ed-9469-abe34def8ed9' -Method 'DELETE' -Headers $Headers

Anyone any idea? 

the api token role is superadmin, so this should not be an issue.

[script]

I would love to hear your thoughts.

Regards,

Arno