localization - lang() does not return value after deployment

Hi everyone,
I followed the excellent localization tutorial https://includebeer.com/en/blog/creating...r-4-part-1 (merci beaucoup Alain) and managed to have everything working on my local machine. I deployed the app to my production server, but there something does not work and I have no idea what I should be checking because I also don't get any error... It looks like lang() does not return the value it should, but only the key??

For example I am getting this:
Home.pageTitle
Home.pageText 

instead of their value when I call 

PHP Code:

<?= lang('Home.pageTitle') ?>
<?= lang('Home.pageText') ?>

I have no clue as what I should be checking to fix this... and would appreciate your help.
Thanks a lot 

// Edit
I found this thread that gave me hope: https://forum.codeigniter.com/thread-77763.html as my files were as well missing the uppercase first letter... but that's not it yet.
I checked my phpinfo, and there is something that might be explaining this – but I have no idea how to solve it:

Code:

intl

Internationalization support => enabled
ICU version => 67.1
ICU Data version => 67.1
ICU TZData version => 2019c
ICU Unicode version => 13.0

Directive => Local Value => Master Value
intl.default_locale => no value => no value
intl.error_level => 0 => 0
intl.use_exceptions => 0 => 0

json

json support => enabled

libxml

libXML support => active
libXML Compiled Version => 2.9.10
libXML Loaded Version => 20910
libXML streams => enabled

mbstring

Multibyte Support => enabled
Multibyte string engine => libmbfl
HTTP input encoding translation => disabled
libmbfl version => 1.3.2

Could it be that HTTP input encoding translation => disabled?

I found this thread that gave me hope: https://forum.codeigniter.com/thread-77763.html as my files were as well missing the uppercase first letter... but that's not it yet.

It actually was the issue , part of my files were missing the uppercase first letter, I corrected that, but forgot to also correct one call still using the lower case from the view I did not see... 
Sorry for the double thread. Problem solved