I can't wrap my head around why my code won't pass 1 of the tests

I’m learning Java, and I’m stuck on the Robot Name, where my code won’t pass 1 of the tests.

import java.util.HashSet;
import java.util.Random;
import java.util.Set;
import java.util.stream.Collectors;

public class Robot {
  private String name;
  private Random random;
  private static Set<String> names;
  public Robot() {
    names = new HashSet<>();
    this.random = new Random();
  String getName() {
    return this.name;
  void reset() {
  private void generateName() {
    String name;
    do {
      name = generateNameLetters() + generateNameNumbers();
    } while (names.contains(name));
    this.name = name;
  private String generateNameLetters() {
    return random
        .ints(2, 65, 91)
        .mapToObj(codePoint -> (char) codePoint)
  private String generateNameNumbers() {
    return random
        .ints(3, 0, 10)

I’m failing test robotNamesAreUnique, where it generates 5000 unique names, and my code just falls short of 5000 and I just don’t know why. Any ideas?

I don’t do Java, but does your code by chance reset the set of unique names every time you generate a new robot? (in the function public Robot()). Is there a way to setup the set of names only once, at the start of the program?