API call didnt work

So deployed a backend project of mine to do somebasic api calls to add to my database
These calls worked on my local machine but when i tried the deployed api routes 1 specific post route wasnt working no matter what i changed

in the end i made a fresh render project and took the exact same code and reployed the who project without changing anything from the previous code
and i called the post api call and it worked
i dont know wat exactly was the problem but i am afraid it might occur again in the future
so if please share yours insights,suggestions if any