when you play the bass do you positionl your wrist so that your fingers come down on the strings (like a thump, but not a slap) or so that they go across the strings the same way that a pick would (like a pluck).
I rarely use a free stroke - where my fingers pluck the sring into my palm. I prefer using a rest stroke - where my fingers end up on the adjacent string after plucking the string (except, of course, the E string).