The Studio flow hits POST /api/v2/conversations/cobrowse/sessions with {"type":"cobrowse","contactId":"xyz"} and the API spits out a 400 Bad Request. Error body is just {"code":"validation_error","message":"Contact not found in conversation"}. Contact’s active in the queue. Token scope has cobrowse:write but calling conversationsApi.postConversationsCobrowseSession() just hangs on the timeout.