WEBENCH Power Designer - LM5116 question

Other Parts Discussed in Thread: LM5116I used WEBENCH to design a DC/DC with LM5116. 40 to 100V input, 30.5V out @ 1/2 amp. Built design on TI Buildit board and tested ok. Layed out PCB used same components except Output MOSFETS. The design works at half load but output voltage droops at full load (1/2A). Can't find anything wrong, checked all parts etc. Working on getting more output for a few weeks without success so I need help. John