Background of the issue:
I am trying to translate a meta field value for a custom post type (CPT) on my site hidden link, but the CPT itself is not translated.
Symptoms:
The CPT is not translated, which is preventing the translation of the meta field value.
Questions:
How can I translate a meta field value if the CPT is not translated?
Welcome to the WPML support forum. Before passing this thread to my colleague, I would like to share some suggestions and possible solutions for the issues you mentioned. Sorry for the late response because of the holidays. It is not normal here.
Please note that it is not possible to translate a custom field if its parent post has not been translated, because custom fields depend on a post and are stored in the postmeta table as child entries.
Also, if a custom post type (CPT) is set to Not Translatable, it will be accessible in all languages. Please refer to the following docs for more details.