Sound effect is not seamless

When I loop my sound effect in Audacity, it loops perfectly.

However, when I import it into Unity, it has a slight part at start and end where it is muted. And when it’s looping it sounds horrible. (see image below) Also, I’m using .mp3 audio extension. Thank you.

I exported it as an .ogg instead of an .mp3 and it had no muted parts.