Google announced that starting January 7th, 2020, Google will no longer serve personalized ads or support features such as comments, stories, live chat, notification bell, and others on videos designated "Made for Kids". This is a setting that can be set for your YouTube channel or for each video that is uploaded to your YouTube account. This link https://docs.google.com/document/d/1Ws2MJSkgtAbq5SOZeL0hLWY_J8vRySX-YXb2SaHBrq0 shows how to set your channel to be “Made for Kids” or to set it for each video that you upload.