Different homepage for mobile - not working suddenly

I found the following code on the forum and added it to give me different home pages for desktop and mobile:

@media (max-width:640px){#your-desktop-page-URL {display:none!important}}

@media (min-width:640px){#your-mobile-page-URL{display:none!important}}

For my purposes, that means it is the following in my custom CSS section:

@media (max-width:640px){#home{display:none!important}}

@media (min-width:640px){#{display:none!important}}

When I added it, I checked it on my phone and it worked fine. But now I had some other people checking through my site, and they told me it wasn't working anymore. Sure enough, I checked my phone and...not working. It's only going to the desktop home page.

I hadn't changed the code. I rechecked it, and it seems to be what I am supposed to have. What am I missing?

Hi. Can you share link to homepage? We can check easier