[Cerrado] ACF fields missing from advanced translation editor

Background of the issue:
I'm trying to set all ACF fields to be used with the advanced translation editor for automatic translation on enlace oculto. I've set most fields to the same fields across different languages and in WPML settings, I've set all custom fields to copy once.

Symptoms:
The WPML settings for custom fields seem to reset for some fields when I save a page and then try to edit them and some fields are missing from the advanced translation editor.

Questions:
Why are the WPML settings for custom fields resetting after saving a page?
How can I ensure all ACF fields are available in the advanced translation editor?