What app is supposed to be a very secure app for communications? I don't personally believe that to be the case but that's beside the point. so likely scenarios that there are some permission problems to audio and video being recorded while you're also sending a video. That's probably what's going on. Similar to how a lot of banking apps at least in the United States do not allow screenshots or screen casts while the app is open. It probably have something to do with that kind of permission issue.
