Missing alt text from CMS

Hi, we’ve set up a blog collection using two template pages: one for each individual post, and one hub page. Each individual post includes a main image, and a (populated) field for alt text. The hub page features a thumbnail version of the image, with an instruction to pull the alt text for the main image (see screenshot below). Yet ahrefs is reporting missing alt text on all of them . I cannot figure out what is going on – can anybody help?
Screen Shot 2022-11-01 at 4.57.26 PM

Here is my public share link: LINK
(how to access public share link)