Missing space in chapter header (RTL text - Hebrew)

[Im_ri]

Hello all,
I'm trying to have the chapter name on each header of the left side page of my book.
To do this I've added a field to the header as shown in this screenshot.
The thing is that something weird happens when the chapter name starts with a digit and not letters - the space between the number and name disappears.
See this example
When I add a letter to the beginning of the name it looks fine. See this example


Any idea how can I fix it? It doesn't happen if I change the chapter name into English characters.

Here is also a link to the original doc.

Thanks a lot!!