The language switcher will appear only if the translation of that page is completed 100 percentage? did you fully translate the page and completed 100% ?
You have to have green 100% here: hidden link when you do that.
Please go to WPML -> Languages->enable "Link to home of language for missing translations" and "All posts (display translation if it exists or posts in default language otherwise)."
Do you see the language switcher after that>
Add a footer language switcher, what are your results ?
Please go to WPML => Support , and click on "Troubleshooting" while in the Troubleshooting page please perform the actions. (specifically "set language information" but i recommend performing all of them"