LT8390

Hi all,

I'm using ic LT8390 in buck region with: Input 36V (This value is output voltage of ic LT8705) and output which I need is 24V. But, output voltage of LT8390 is oscilated, and volatage value is not 24V. If I use input is lower 30V, output voltage is exacted 24V. Can you help me explain for this situation?