How to Tag a mail with a blue arrow when forwarding it via MimeContent

Question

Hello, I'm trying to forward an e-mail via MS Graph. But since I have to decrypt the Mail before forwarding it, I thought the best solutions would be to send the Mime Content of the message in order to forward it. I've been following official Microsoft the docs to forward a Message and I am forwarding the message like this:

StringContent stringContent = new(base64String, Encoding.UTF8, MediaTypeNames.Text.Plain);

RequestInformation forwardRequest = _graphClient
			.Users[_graphSettings.MailAddress]
			.Messages[mailId]
			.Forward
			.ToPostRequestInformation(new ForwardPostRequestBody());
		
forwardRequest.Headers.Clear();
forwardRequest.Headers["Content-Type"] = new [] { MediaTypeNames.Text.Plain };
forwardRequest.Content = await stringContent.ReadAsStreamAsync(cancellationToken);
await _graphClient.RequestAdapter.SendNoContentAsync(forwardRequest, cancellationToken: cancellationToken);

Normally, when you forward a message via the other route like this:

ForwardPostRequestBody body = new() {
			ToRecipients = new List<Recipient> {
				new() { EmailAddress = new EmailAddress { Address = forwardToMail } }
			}
		};

await _graphClient
		.Users[_graphSettings.MailAddress]
		.Messages[mailId]
		.Forward
		.PostAsync(body);

Outlook displays a small blue arrow next to the mail, signaling, that it has been forwarded: but this doesn't happen when you upload the MimeContent as seen in example one. I've tried to update the MAPI Properties myself like this:

await _graphClient.Users[_graphSettings.MailAddress].Messages[mailId].PatchAsync(new Message {
			SingleValueExtendedProperties = new List<SingleValueLegacyExtendedProperty> {
				new() {
					Id = "Integer {00062004-0000-0000-C000-000000000046} Id 0x1080",
					Value = Convert.ToString(0x00000106)
				}
			}
		}, cancellationToken: cancellationToken);

but this does not change the fact that the blue arrow is missing. I just add a custom SingleValueExtendedLegacyProperty which does not change the displayed icon.

And now to my question: Is this intended? Is the blue arrow supposed to be missing when I forward a mail via uploading the mime content? Is there some other way to update the status of the mail to something like IsForwarded with the graph sdk or am I just supposed to use the other forwarding method in which I update the message instead of uploading the mime content?

Thanks in advance