Child theme .mo file not being picked up

Hello,

I’m using a child theme and stored the translations in a .mo file under /wp-content/languages/themes/apicona-child-fr_CA.mo

My theme is internationalized using the __() function.

When I’m loading the page in French, the text remains in English.
I’ve been reading many posts about localization but I cannot find the reason why this is not working.

It is also the case in my admin interface. I created custom post type and taxonomies in the functions.php file and stored their translations in the same child theme .mo file. However, they are not being translated in the admin.

Are you able to help with that?

Thank you,
Arnaud

https://wordpress.org/plugins/polylang/