This thread is resolved. Here is a description of the problem and solution.
Browser language redirect only works once.
Yes, this true the browser language redirect of WPML only works once. From our documentation at the following link: WPML will do this language redirect only once and then not redirect anymore. We do this to allow visitors to still switch languages. If we always push back to the browser’s language, visitors will not be able to manually switch languages after WPML redirects them to the language set by their browser. This single-time redirect operation resets every 24 hours (which you can change too).
Please also be aware that browser language redirect might affect Google indexing. You can read about it in our documentation here.
This is the technical support forum for WPML - the multilingual WordPress plugin.