LM5066: Driving issue for 6pcs MOSFETs

Hi,

I have a drive issue about using LM5066 to drive 6pcs MOSFETs parallel.

The channel of waveform shown as below are Input voltage(CH1), output voltage(CH2) and Vgs(CH4)

If the output Load is 0A, the Vgs signal of Mosfet rise smoothly.

When output load is a small load, like 2~5A, the Vgs signal reach mosfet threshold voltage for a while, then GS, DS of Mosfet are burns. 

But if I use 1psc mosfet and add one capacitor  across gs terminal to simulate same Ciss of 6pcs mosfet.

Mosfet wolud not burn when output drawing the power.

How to check if  I can support 6 or more MOS parallel?

Thanks.