If you are using the builder to create the post type (via UI), please generate the PHP code and add it to the file functions.php in your theme/child theme folder and use a translation plugin like Loco Translate, WPML to translate the CPT strings.
Thanks Long Nguyen for your workaround, although it's not really a user friendly solution IMHO.
ACF offers native language for all labels, so why not just providing the same solution?
The post type created by Meta Box might be different from other plugins. The CPT is saved in the database as a post (post type mb-post-type) so it might not work with some translation plugin and you have to use the code to register the CPT and translate the label.
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