Error 500 adding a sub-item to an item

[Scal-Human]

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Hello,

I receive an error 500 when adding an issue (2) as sub-issue of another (1).
I tested a little bit everything I had in mind both following and deviating from the documentation with no luck:

• with/without Accept header
• with/without Content-Type header
• with/without an 's' to "sub-issue" (as the DELETE path is without), idem for "issue"
• I verified the GitHub status where everything is green.
• I tested a lot of other endpoints without problem (so the issue is not between the keyboard and the chair, and I am not a newbie)
• I even tried with PUT and PATCH, just in case (here the error is the expected 404).
• I tried with both types of token
• I tried an organization repo and a user repo with the same result

$owner = ... ; $repo = ... ; $token = ...
$headers = @{ Accept = "application/vnd.github.raw+json"; Authorization = "Bearer $token" }
$url = "https://api.github.com/repos/$owner/$repo/issues/1/sub_issues"
Invoke-WebRequest -Method POST -Headers $headers $url -Body '{"sub_issue_id":2}' -SkipHttpErrorCheck
StatusCode        : 500
StatusDescription : InternalServerError

It is frustrating as it works in GitHub.com, but not with the API, and I need it for my usecase.
Can somebody explain what is happening ?

[github-actions[bot]]

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