I output the input line in via std :: cout << maze

And you forgot to separate each output so what you see is multiple mazes concatenating to each other.

I'm sorry to say this, but if you're making newbie mistakes like this and can't realize the mistake at all, maybe you still need to work a lot harder before attempting this kata ;-)

Because you're not interpreting the logs correctly?

the line has no solution

And how do you know that? Are you sure you're interpreting the messages correctly? Specially for you, just to be 200% sure I've looked through the "snake" cases, and they are all correct.

your test says that there is a way out of this labyrinth, but according to the logs it is not

What logs? This is a valid test.