Calling User.setProxyAddresses() results in "Insufficient privileges to complete the operation" even with elevated permissions

Expected behavior

Making a call to User.setProxyAddresses() succeeds when "User.ReadWrite.All" and "Directory.ReadWrite.All" application permissions are granted in the Azure portal with admin consent given.

Actual behavior

An exception is thrown:
com.microsoft.graph.beta.models.odataerrors.ODataError: Insufficient privileges to complete the operation.

Steps to reproduce the behavior

Using version 6.9.0 of the beta SDK:

• Create a new user (post)
• Attempt to update user (patch) with a call to setProxyAddresses() made first
• Observe the error

Here are the permission settings we tried using in the Azure Portal:

We also set the application in Azure to both User Administrator and then Global Administrator without succcess.

Related

Patch request to do the same operation is the suggested operation via graph explorer:
https://stackoverflow.com/questions/65198916/remove-old-proxyaddress-entry-for-user-in-azure-active-directory/71577425#71577425