LM5116: LM5116_ Buck converter

Hello,

Thanks a lot for introducing LM5116 instead of LM25149.

I want to design a buck converter with 54V input and output with 24V and 3.5A. I could design it based on the quick start calculator of LM5116. I achieved this result individually( attached) but when I connected to the rest of my design (with 54-volt bus voltage), I couldn't get a good result. I think the buck controller moves to the HICCUP mode because the output of the hysteresis comparator just goes up to 15V instead of 54V(previous level) and then goes down and then this story repeats.

Please help me to find my mistake.

Thank you,
regards,
Leila