Would you be willing to provide me with WordPress credentials so I could investigate the issue directly?
And send me this in order to understand which parts are :
- a page or page in question (at least one example) where the issue is to be seen
- screenshots would also help me understand this - screenshots on that post/page
From your screencast, I understand that you are looking at the wrong menu.
Our documentation says that you need to go to Users -> Your profile and not Settings -> General.
I have prepared a screencast for you :
hidden link
As you can see I am able to change the language from there in ENG or ES.
Some more details are :
1) The top language admin bar has nothing to do with the administrator language, but with content language, for example, Post, Page content translations
2) If you change the administrator language and some parts are not translated, that means that the plugin author is not added the proper translation language. You can use WPML String Translation to add your translation