Webench/LM3488: unstable circuit in LM3488

Tool/software: Webench

Hi

I use webench to run LM3488 (uncouple SEPIC circuit; as attached file), Vin=4.75~5.25V; Output is 5V/3A, but can't not work actually in my PCBA (the load >200mA, the Vin will from 5V drop to 3V(OCP 3A)).

pls help chek this webench issue.

thanks~

webench_design_LM3488.pdf