Fn function terminates before timeout

Question

I have set the timeout in func.yaml to 300 seconds (5 minutes) but the function only runs for 2 minutes and then terminates with error code 502.

Error invoking function. status: 502 message: error receiving function response

There is a github issue that discusses this problem: https://github.com/fnproject/fn/issues/723

How do I resolve this problem?

Edit:

As an example, I created a nodejs function which should respond after 270 seconds but doesn't due to early timeout.

fdk.handle(function(input){
    return new Promise((resolve,reject)=>{
        setTimeout(()=>resolve("Hello"),270000);
    });
})