Hi there
A couple of notes on the translation process for the wishlist title:
1. First of all, you should change the option for the default title, since it is probably stored in your database as an english string:
You can find the option under WP Dashboard -> YITH -> Wishlist -> Wishlist page options -> Text customization: here a screen
2. Then, you’ll need to test with a new user/incognito session, since when a wishlist is registered in database, its name will be permanentely saved, and at that point it won’t change, even if you alter plugin configuration
