Bug with typing numbers (Japanese)


I have a problem with my Japanese learning.
When I have to type answer in Japanese and it’s starting with numbers, Memrise accept any answer that will start with that number (or just number).
For example, I have phrase in Japanese
50 ねんまえのふるいおさけをのんでみたら
And it’s English translation ‘On trying the fifty-year-old-sake’. The problem is, when I typing the answer, Memrise accept just ‘50’.
I uploaded a screenshot to be more clear.

Thank you for your great website.

Here is one more screenshot

Hi there,

Thank you for contacting us. Could you send me the link to this course so that we can see if there is something special in their setting?



Originally I had problems with this course
But I edited it so that now no phrases starts with numbers (added ね。in front of such a phrases).
I created new course to show you this priblem. Here is the link

Thank you for your help.