Why is my kitchen faucet dripping even after water is shut-off?
both or one of your shut off valves is not shutting off completely and has a small drip which builds up in the cartridge housing. the new cartridge fills that void up causing it to leak again. 

This is the only logical explanation i can think of.

You didnt say if you replaced the cartridge with a new or seals.  So if not the do so and it should stop leaking if you do it right.