This has been an issue for the past year or two. It sucks that it's starting to affect people more and more just because they are in that grey area between child and adult content.
COPPA is a new law that is super overprotective of anything that could even be slightly considered childrens content and thus if your video is deemed to fall under these guidelines you will be forced to have it be set for kids meaning you cannot comment and it wont suggest the video to the algorithm