Translation of Menu items
First of all, when you search for translations they are case sensitive. don't include aditional spaces, it has to be exact, but it can be partial.
If one translation was previously made and the same word appears in many places it will list it, but what applies is the first translation made (sorted by time)
You have to make sure that your Log Out is really a tranlation

in my case it appears in chain: /admin/settings/language as Log out @username, so if I translate this, it works in the other languages
there is another Log out in the chain with the same name...so be careful