Screen reader not reading alt text

I’ve created a page and have gone through all of the code. I have alt text correct in the HTML as well as in the media library. However, the screen reader for Safari won’t read the alt text and instead skips over the graphic entirely. Is there a way to fix this that I’m missing? I’ve triple checked all of the coding as well as the alt text tags in both the media library image itself and in the post itself.