[Resuelto] Flag alt tag

Background of the issue:
I am trying to add an alt attribute to the language flag icons on my site enlace oculto using WPML. I found a solution on https://wpml.org/forums/topic/how-can-i-add-and-alt-attribute-to-the-language-flag-icons/, but it only works until updates are made, and then the issue returns.

Symptoms:
The solution to add an alt attribute to the language flag icons is not persistent after updates.

Questions:
Is there an option to make the alt attribute solution permanent even after updates?