I recently updated the alt text of the image files on a website via the WordPress media page; however, SEMRush and Screaming Frog both cannot detect the updated alt text. I used the "Inspect element" option to check the page where the images in questions are attached, and the updated alt text does not show there either.
Someone explained that it's a WordPress quirk and that when the alt text of images are updated, the updated text will only show up "wherever you insert the image thereafter," and if I wanted the updated alt text to appear in all posts where the images are used, I would either have to reinsert the images or update the tags of each image in the post.
I'm not sure how to do the latter.
Another question I'm wondering about is, I can only see 150 or so images on my Wordpress Media page, but SEMRush detects about 300 or so.
The site uses an image optimizer plugin, so I am guessing the other images that SEMRush detects are probably resized versions of the images that I can see on the Media page (?), but I was wondering where they are because the total number of images on the Media page and the SEMRush audit does not add up.