html - Android monospace space ( ) width is different than character width

I'm developing a little webapp.

I tried displaying some output in an sort of ascii art way, using boxdrawing characters.
However, I noticed that on Android the space ( ) isn't equal width with the other characters, leading to ugly output.

I've put the font as monospace and even tried the monospace,monospace CSS setting.

To see what I'm talking about:
Please open https://tpgnow.herokuapp.com/CERN on Android and on a desktop browser.

Expected Output (desktop browser):

Actual Output (android browser):

I've tried different browsers and platforms and devices.
It seems to work on Win, Mac, Chrome and Firefox, also on iOS, but not on Android (neither Chrome nor Firefox).

Does anybody have a solution for this problem?