Why is a product that I've boosted showing behind a product that has no boost rules applied?

Hawksearch considers any Boost or Bury Rules in a product's score. A Boost or Bury Rule will affect a products score but relevancy still plays a factor. Applying a Boost or Bury Rule does not take precedence over score. So if there is a product that has a higher score than the product that has a Boost Rule, it will appear before the boosted product. To ensure that a product shows in the top positions, the pinning functionality should be applied.

See also Best Match.