Boolean confusion in JS

Question

A challange question I tried to recreate as JS code gave different results, I do not understand the reason. ( Tried looking for similar topics on boolean, but still confused.)

The JS code is:

let a=0, b=2;
// the first time will result in 0
document.write(a++&&++b);
console.log(Boolean(a) +" a");
console.log(Boolean(b) +" b");
console.log(Boolean(a++) +" a++");
console.log(Boolean(++b) +" ++b");
console.log(Boolean(a||b) +" a||b");
console.log(Boolean(a++&&++b
) +" a++&&++b");
// now the result is 5. Why?
console.log(a++&&++b);