Bug#1017109: Bug #1017109: www.debian.org/devel/website/stats/ works only in English

Hello all
After upgrading www-master from Debian 10 buster (wml 2.12.2) to Debian 11 
bullseye (wml 2.32.0), we experienced an issue when building the
stats files for the website (https://www.debian.org/devel/website/stats/* )

I could set up some work around in the Makefiles so the pages in English 
language are built correctly, but couldn't make it work for the other languages.
Thus, if you for example go to https://www.debian.org/devel/website/stats/fr.en 
you see the correct stats for French language (page displayed in English), but 
if you go to https://www.debian.org/devel/website/stats/fr.fr or 
https://www.debian.org/devel/website/stats/fr.es (e.g. to see the French stats 
displayed in French or Spanish), these pages are outdated.

I have removed the outdated html files from www-master (it will be propagated 
online in the next hours), so for now, until the bug is fixed, the pages are 
displayed in only English but with current stats.

If anybody can have a look at the bug report and have any idea of how to fix the 
issue, any help is welcome:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1017109

Thanks