If this work was done a thousand miles ago, then one of two things is happening. It was leaking and you just discovered it..or..something nasty just recently occured. If the ATF is coming thru the grate and not tracking from the front edge of the pan(unlikely but possible), then it's either the torque convertor or the front seal on the tranny. Quick diagnosis for you. Get the car up in the air with the engine running (observing all safety precautions). Get a can or two of spray brake parts cleaner with the little red spray attachment. Direct the spray with the little red nozzle thru the grate and spray it on the touque convertor as it is rotating, then spray the grate, the idea is to remove as much residual ATF as possible.. Stand back and observe the grate. If it starts showing fluid right away, kill the engine, rotate the torque convertor until you can eyeball the drain plug. If that's dry, then it either the front seal has blown out or, ug!! something has cracked or broken, torque convertor, front cover or the case itself. It concerns me that you stated that shutting down the engine stopped the flow of ATF which makes it sound like it's pressure related. Try thses things to see if you can narrow it down.. Good Luck.
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.