TPS54260 24V to -15V design

Hello Everyone

I designed an inverted power supply with input voltage of 24V and output voltage of -15V using TPS54260. I used the calculator as well as reference designs from the TI website. But unfortunately the power supply is producing around -7 volts instead of -15V. I am attaching my design as well.

I tried to change the Cin as well but of no use.

Any help in this regard is highly appreciated.

Thanks and regards;

Lee