DC-DC Converter Unusally Low Load Capability
You made a significant change in the inductor, from 4.5 &micro;H to 3 &micro;H.  The smaller inductor will hold less energy at the same current, and will reach the current limit quicker.  Also, make sure the 30 m&Omega; sense resistor really is 30 m&Omega;.  If that is a larger, then obviously the device will limit the inductor current to a lower value.