TPS2419: Cant' start in 75C temperature

Part Number: TPS2419

Tool/software:

Dears:

Customer use TPS2419 to do 3.3V oring, they found below circuit has abnormal high temperature issue

1- Vin=3.3V, load=1A, when do 75C high temperature test, board can't start when store over 5 minutes.

2- It can work normal in 25C and -40C temperature. 

3-When start in 75C with 1A load, MOSFET GS voltage is very strange. 

Could you please help check what happened ? Thanks.