Difference between Peak rectifier vs Full wave rectifier
The difference here is that a diode allows current to pass in one direction, while the FETs (while on) allow current in either direction.  Presumably, NXP designed it to keep the appropriate FETs on at any time one of the input voltages is higher than the other.  Since you're conducting through the entire half-cycle, your capacitor is being discharged through the bridge as well as being charged.  The FETs will stay on until the input polarity reverses, while the diodes will stop conducting anytime the instantaneous input voltage is lower than the voltage on the cap.