Flex particles bunching up from runner with velocity

I’ve been working with Flex fluids for a while now inside UE 4.19.
It’s great, creates some cool effects. Now…say I have a player running with a spray nozzle emitting flex particles. Works fine while walking slowly but when the player starts picking up speed the particles begin bunching up, colliding, and making a mess.
Seems that the velocity of the player is not being inherited into the flex particles.
I’ve tried increasing the emission velocity but then I start getting bunching up even sooner.
Is there a trick to this that I’m missing?
Thanks for any help! I’m stumped.