Adding external reference to PlannerTaskDetails results in dangling name exception

[JackieDanes1990]

Describe the bug

I am using the latest version of the library, and I'm trying to add some links to PlannerTaskDetails.
Given the PlannerExternalReference is not generated for the library, I created my own record that matches the documentation ( https://learn.microsoft.com/en-us/graph/api/resources/plannerexternalreferences?view=graph-rest-1.0 besides the type, which seems wrong and doesn't match up with the explorer so I replace that with microsoft.graph.plannerExternalReference).

I have a list of URLs, so on my details => plannerExternalReferences I then call setAdditionalData with a map of String, and my PlannerExternalReference record, where the String is my url partially escaped in the same manner in the documentation.

Running this code results in an exception in the form of: dangling name https%3A//contoso%2Esharepoint%2Ecom/teams/agile/documents/AnnualReport%2Epptx

Expected behavior

To have reference(s) added to my task.

How to reproduce

Mentione in the description

SDK Version

6.55.0

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

Click to expand log

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### Configuration

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### Other information

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