I was able to fix the issue. The solution is a bit iffy, so if anybody can provide a better solution I’d be more than happy to hear it.
The problem is that ACF outputs an absolute path to the page/post/etc. when using a Page Link field, but WP All Import requires either a post ID or slug to make it work. I have no idea why they wouldn’t accept an absolute path, but they don’t.
Running a simple find and replace on the exported CSV file to keep only the ending, hence the slug, worked. Even though I had to keep the last /, WPAI remade the connexion.
The iffy part is in the admin. I don’t directl see the reference to the page/post, but the absolute path. No idea why, but it works.
