notablet nomobile don't work

Hi,
I read here
https://www.gavick.com/documentation/jo ... ve-layout/
“To suppress a module from displaying on both the tablet and mobile devices, apply both suffixes simultaneously, such as: “ notablet nomobile” (and remember to place a space at the beginning of each suffix”

I’m building the site of my University association http://ldf.tekne.eu.com/
In the top position I placed some modules with “ notablet nomobile” but suffixes don’t work, the modules don’t desappear in tablet and mobile devices. What is wrong?

Please, could you help me?

Ciao

PS
Moderator, please may you hide my site address in the post? Thanks

Apparently the solution is simply to use the suffix "onlydesktop" instead of "notablet nomobile"

That didn't work for me.