We got the problem with WPML, and please see the following link:
The menu bar of spanish is gone compared with english page. Also, page content has not been translated yet.
We figured out the menu bar issue, but, still can not translate the content. When we try to edit the translation page, miss the original content in that page.
The following is the original page, and you can tell some content doesn't show above.
We means when we try to edit the translation, some content missed in that page, so that we can not edit it at all.
Maybe, my installation of betheme has some bug!
Please, check the following video tutorial, and ensure that you do all steps correctly.
We followed this video to install it.
We also check the video you provided, and we think we have the right setting as following:
But, still same thing, and some content still missed in the translation page, and maybe, we should say those content flash in the translation page, then, gone.
For example, supposed 4 line should show in the page to allow us to edit. But, those 4 line content don't stay in the translation page. Just flash, then, gone.
Also, we check advanced translation editor error logs, and found some error message as following:
Please, turn off all of the plugins except WPML, refresh your cache, and check if the problem persists.
Moreover, if you are using a child theme, switch to parent, and recheck it.