Code:

public class Test {
  void test(Object obj) {
    switch (obj) {
      case Integer _ when ((Integer) obj) > 0:
      case String _ when !((String) obj).isEmpty():
        System.out.println(obj + ": Positive number or non-empty string");
        break;
      default:
        System.out.println("other");
    }
  }

  public static void main(String[] args) {
    new Test().test("");
  }
}

This program can be compiled correctly (expected) and prints (unexpectedly)

": Positive number or non-empty string"

It should print "other", as guard condition is not satisfied. Note that if I remove never taken "case Integer _ when ((Integer) obj) > 0:", then the string guard is taken into account.