"Ви говорите за скоро!" should also be accepted.
This is how we have been speaking in the West for centuries.
It was marked wrong!
Ви занадто швидко говорите - не працює. В чому помилка?
Все вірно. Немає помилки.
"За швидко" was also marked 'wrong' when it should be accepted. People use these words today.