While we can't go into specifics. Can you get in touch with our Creator Support team? Here's how: https://goo.gl/BxLi8H . They can dive into the details with you. Hope this gets resolved.
Thanks for trying. To clarify, discovery of your videos depends on multiple factors like tags, title, description, etc. We recommend taking a look at our Help center article on Discovery optimization tips which talks about how to attract more audience: https://goo.gl/vJB5SW