Well, I was googling for the same problem and by reading this page I got inspired and I found the solution.
In my case the numbers that would not behave where among text in greek language.
The solution: just change the language of the numbers to almost anything other (than Greek Language) they do behave as expected.

It’s obviously a bug that affects only some languages. I do not see any Japanese option and I have not checked every language available but it happens with greek language.
Hope this works with Japanese too :)