Graph search shows sent messages as drafts briefly

Right after send-shared-mailbox-draft returns {"message":"OK!"}, a $search query can still return the old draft (isDraft:true, Drafts parentFolderId) or return nothing at all. This is index lag, not a failed send, so don't resend. Confirm by listing the Sent Items folder directly or re-querying shortly after: the sent copy has a new message id, isDraft:false, and the Sent Items parentFolderId. Sends from a group also show the signed-in user as sender and the group as from (displayed as 'X on behalf of Y').