return type not getting inferred correctly. what am i doing wrong here?

type Person = {
  name: string;
  age?: number;
};

// should return array of numbers or undefined
const getAgesOfPersons = (persons: Person[]) => persons.map((person) => person.age)

// should return array of numbers but returns array of numbers of underfined
// is inference broken here?
const getAgesOfPersons2 = (persons: Person[]) => persons.map((person) => person.age).filter((age) => typeof age === "number")

type Person = {
  name: string;
  age?: number;
};

// should return array of numbers or undefined
const getAgesOfPersons = (persons: Person[]) => persons.map((person) => person.age)

// should return array of numbers but returns array of numbers of underfined
// is inference broken here?
const getAgesOfPersons2 = (persons: Person[]) => persons.map((person) => person.age).filter((age) => typeof age === "number")