Impossible to stick my element

Hello

on my website (still in beta version), https://collectifsaga.com/X/wordpress/fr/home/, I want to stick the menu (the filters “architecture”, “…”)

I hope I’ll be able to to it, but for now I can’t.
According to Firebug, the name of my class is “.esg-filter-wrapper”

But I does nothing. I tried with an other one, just to try (the logo on top left, which is already fixed with CSS), but I doesn’t work either

Do you have an idea how to solve my problem ?

Thanks a lot

https://www.ads-software.com/plugins/sticky-element/