I finally found the one that worked

First time I saw a menu sticking, I knew I wanted to have it in my website.
It took me some time to find one that would work but then finally I found Lowermedia Sticky js menus
It does exactly what it proposes…and works perfectly on my bilingual site.
Here are examples of the same pages in two different languages:
https://foradazonadeconforto.com/como-escolher-e-comprar-seguro-de-viagem/ (Brazilian Portuguese)
https://outofyourcomfortzone.net/how-to-buy-travel-insurance/ (English)
Simple and great plugin.