Get CallTranscript, Docs do not match current API, Cannot set file type.

This code worked until I updated to the latest library:

var istrm = await m_graphClient
.Users[admin.Id]
.OnlineMeetings[meeting.Id]
.Transcripts[transcript.Id]
.Content
.GetAsync();

Now I get this error:

Invalid format 'application/octet-stream, application/json' specified.

The say I should be able to set the format:

https://learn.microsoft.com/en-us/graph/api/calltranscript-get?view=graph-rest-1.0&tabs=csharp

// Code snippets are only available for the latest version. Current version is 5.x

// To initialize your graphClient, see https://learn.microsoft.com/en-us/graph/sdks/create-client?from=snippets&tabs=csharp
await graphClient.Users["{user-id}"].OnlineMeetings["{onlineMeeting-id}"].Transcripts["{callTranscript-id}"].Content.GetAsync((requestConfiguration) =>
{
	requestConfiguration.QueryParameters.Format = "text/vtt";
});

But the "Format" property is not defined in the version of the library I am using (5.38.0)

How can I fix? Seems like a bug in the release.