Unable to delete a chat member from another tenant

[chrisbardon]

Describe the bug
I created a graph application that did the following:
-In tenant A, created a group chat (as user 1), and added user 1 (tenant A) and user 2 (Tenant A) to the chat
-Added user 3 from tenant B by AAD ID to the chat
-Attempted to remove user 3 from the chat using await m_graphClientUser.Chats[m_chatID].Members[memberID].Request().DeleteAsync();

This throws an exception :

Code: NotFound
Message: The requested instance was not found. Id:'MCMjMCMjOGM2YWUxNzItYTNlYS00ZjUwLTk5NGQtYTAyNTY4MjI2OTdmIyMxOTpiNTkyNjYwYzhiMDk0ODJkYTRjODM0ODEwM2ViYjIzMUB0aHJlYWQudjIjIzRhMTJjZmU4LWQ3YzktNGVkMi05NDc4LWMzYzE3ODlmNTFmMQ=='.
Inner error:
	AdditionalData:
	date: 2021-08-20T16:15:47
	request-id: 5a8a9d07-9214-4fc9-be94-c001d255ddf6
	client-request-id: 5a8a9d07-9214-4fc9-be94-c001d255ddf6
ClientRequestId: 5a8a9d07-9214-4fc9-be94-c001d255ddf6

To Reproduce
This is the code I used to remove the user. Note that I'm querying the membership to get the member ID immediately before calling delete:

                string targetID = "4a12cfe8-d7c9-4ed2-9478-c3c1789f51f1"; //aad user ID to remove
                string memberID = null;
                var members = await m_graphClientApp.Chats[m_chatID].Members.Request().GetAsync();
                foreach(var m in members)
                {
                    if (m is AadUserConversationMember && ((AadUserConversationMember)m).UserId.ToLower() == targetID.ToLower())
                        memberID = m.Id;
                }
                if (memberID == null)
                    return;
                await m_graphClientApp.Chats[m_chatID].Members[memberID].Request().DeleteAsync();

Expected behavior
User should be removed from chat. This works if the user is in tenant A, but not if they were added in another tenant.

Desktop (please complete the following information):

• OS: Win10 19043.1165
• Microsoft.Graph nuget version 3.35.0
• Microsoft.Graph.Core nuget version 1.25.1

Additional context
Behaviour is the same whether I'm using application permissions or delegated user permissions to remove the user. Removing user in the same tenant works, cross tenant does not. SDK identifies both as AadUserConversationMember

AB#10802

[andrueastman]

Hey @chrisbardon,

Thanks for raising this issue.

I have attempted the same via graph explorer and I get the same response when the user if from a different tenant.
Since this issue seems to be an issue with the API end, I have raised the question at the link below so that we may get further clarification from the relevant API owners and so that we may track it from there.

https://docs.microsoft.com/en-us/answers/questions/541537/unable-to-delete-chat-member-if-member-is-from-a-d.html

Closing this for now and will reopen this if there are any issues brought up with the client library itself.