Hello Dison,
What current are you testing at for your higher current design? Are you seeing lower voltage at no load? Or is it 150V at no load and then drops when you start increasing load? What is the behavior with the 9mOhm resistor and the compensation components?
I would like to see scope images of the Vout, Vin, Vswitch nodes along with the Inductor current for both your designs. If the layout is not optimized, the resulting noise could cause the controller to fail eventually. Please also send good quality images of your board layout that you have for this design. You could also send Gerbers in addition to this information.
Regards,
Akshay