I traded for many years just my system, and ignored all news.
But since Trump became President, I noticed that the number of losing trades went up and losses became bigger too. I think that there is no system that can avoid losses in these crucial moments as there is no real "nomal" market activity.Even in normal markets it is already difficult to control your positions in a way to make them all profitable.
I studied behavioral finance for years and my opinion is that you cannot efficiently manage your positions in chaos. Even in "normal" markets the majority is not able to make any money consistently. How can you then do that in chaotic or very nervous markets when things happen that can have a huge impact on the market?
EDIT: If your performance depends on the results in these chaotic moments (like FOMC) then you should ask yourself questions about your system. A good system can afford to skip these dangerous moments. Even then it is already a challenge for most traders to make money.