Update immutable Value Object?

Question

Software design

VO update?

class UserName {
    private string $name;

    public function __construct(string $name) {
        $this->name = $name;
    }

    public function update(string $name): self {
        $copy       = clone $this;
        $copy->name = $name;

        return $copy;
    }

Or so

public function update(string $name): self {
        $new       =  new self($name);
        $new->name = $name;

        return $new;
    }

No matter what update, then

$user->setName($user->name->update('new_name_str'));
...
class User {
    public UserName $name;
...
   public function setName(UserName $name){
        $this->name =  $name;
  }
...

VO is notoriously immutable, so how would you go about updating VO or are you already doing it?

PS I'm doing it right now

class User {
...
   public function setName(string $name){
        $this->name =  new UserName($name);
  }
...

Which approach is more appropriate and why?