Reading the comments below I came to the conclusion that my code works correctly.

So, in the case of a = 2 2 3 against b = 4 9 9 -> should return False as it actually does.

Therefore it seems that

"Expected: true but Actual: false" mistake

refers to the other test, which remains hidden because it is the next test :/

Yeah, was stucked was the same issue ...

OK, thank you for a prompt reply

You should write the instructions to print your input or output data directly in your programming window.
For example, I have printed it twicely: at the beginning of test and at the end of it:

for (auto x : a) std::cout << x << " "; std::cout << std::endl;

for (auto x : b) std::cout << x << " "; std::cout << std::endl;

It's C++ ))

Try the test case with data
a = 2 2 3
b = 4 9 9
Here is the bug, I guess.

You are mistaken. Don't raise an issue when you don't know. Please read this: https://docs.codewars.com/training/troubleshooting/

If I am not mistaken my C++ solution fails with the following test data:
vector a = 2 2 3
vector b = 4 9 9

Expected: true, but in my solution it is false, because
4 4 9
not equals
4 9 9?

Any idea upon this case? Wrong test reaction? I didnt understand task conditions properly?

P.S. All random tests were passed successfully.

You can print the input as shown here: https://docs.codewars.com/training/troubleshooting/#print-input

Yeah, I figured that, but sorry this answer does not help my problem.
How am I supposed to figure out my mistakes if failed test does not show?

Before posting issues look at the top of the page: 20831 people passed Js (out of a total of 73969). If tere were errors in the kata somebody would have seen them before you. Sorry.