Font on slider not responding to child css code

Hi All,

Would really appreciate some help on this one…
On my homepage, dentistryon7.com, I’m trying to make the font on the slider white with a shadow. It was like this for some time but lately I’ve noticed (in incognito mode as I am using Wp-rocket which caches pages) that the font reverted to black.

I have this code in my child css theme but it doesn’t seem to be working anymore.

.home-slider .slide-content {
font-size: 40px;
color: #ffffff;
text-shadow: 2px 2px #000000;
margin: 0 0 20px;
font-weight: 500;
}
I’m stumped (and a total beginner) Any ideas??