Background of the issue:
I am trying to translate the subject and heading of emails sent by WooCommerce Stripe Payment Gateway. I expected the subject and heading entered via WooCommerce -> Emails -> Failed Subscription Renewal SCA Authentication to appear in String Translation, as they do for other WooCommerce emails.
Symptoms:
The strings are missing from String Translation. It appears that WooCommerce Multilingual is missing support for translating those fields.
Questions:
Why are the email subjects and headings from WooCommerce Stripe Payment Gateway not appearing in String Translation?
Is there a way to add support for translating these fields in WooCommerce Multilingual?