Not a bug
If you have the option: “Increase speed by disabling do_action calls in wp_insert_post during import” enabled when doing an import with WP All Import, you might have issues with how the posts are imported and that can lead to a number of problems with WPML and potentially other related plugins too.
That option is created for increasing the speed, however, when inserting new post, WPML is doing some magic that makes the post assigned to a certain language.
If that option is enabled, you will not have the content appear in any language and you should run troubleshooting action to set language information afterwards.
This can be especially problematic if you try to insert translations of content as even running afterwards the troubleshooting action will not properly assign the content.
We recommend to disable that option when using WPML