Wrong email is sent (en vs en_CA

Product Support
1

Your software
My Mautic version is: 5.1.1
My PHP version is: 8.2.24

In my Mautic there are contacts with the preferred language “nl” (Dutch") and “en” (English).

I have 3 emails. The language of the “main” email is “en” and there are 2 translation variant. One with “nl” and one with “en_CA” (Canadian English for later use). (Email_en and its translations Email_nl, Email_en_CA)
And I have a campaign which sends this “main” email (the one with the “en” language - Email_en ).
My “nl” contacts get the proper “nl” email version (Email_nl), but my “en” contacts get the “en_CA” email version (Email_en_CA).

I have no idea why…

2

When I change the language of the “en_CA” variant to something else, for example to “hu” (anything, but en_XXX), my “en” contacts get the proper “en” variant.

So I suppose there is some error in the code, because my email/campaign/contact setting seem to be OK.