2014 bmr springs , koni yellow, m/m caster plates., bmr panhard

any of you guys have sound when weight transfer occurs at slow speed Ie . back out of driveway slowly and brake. or driving slowly and brake " oh there's a parking spot"
it's like a " swoosh" or " fart sound" seems only to occur in these situations .
Compression sound?

I have not used the vehicle too much at all been using Wifey's car but decided for some reason to pull it out today. Sound occurred way back but noticed if occuring way more today.

thanks for any input