Targeting the audience with accurate interests can improve performance. Here are the main three things you should check:
The 'Interests' audience is too small and doesn't generate traffic.
There aren't enough 'Interests' included in the ad to generate traffic.
The 'Interests' are not accurate enough to target the right audience, generating traffic but not sales.
in any of those cases, we recommend to first review the performance of your interests under the 'Interests' tab.
According to the specific Interest performance, you can decide if to remove specific 'Interests' and/or add others.