ALT Text In Images

Hi,

I used Website Grader to check the seo on my site. It said that I don’t have ALT text in 7 of my images, so I added them. But now when I use Website Grader to check again, it still says the same thing. Why is that? Do I need to update some sort of cache or something?

https://websitegrader.com/site/www.whatisthatallabout.com

Hope someone can help,

Thanks