Hi Robert,
I’m sorry I didn’t reply earlier; I’ve been under the weather.
In any case, your report did help me find the apparent cause of the issue (a bug at Google), though I don’t have a solution right now; I’m still testing things.
I proposed a workaround here that implements extra structured data for images. This is still being tested, and if it works, I will add it to the plugin. Feel free to use this as well.
Another solution would be to remove the <a>
tags around your images; however, that is not feasible in your situation (it’ll harm accessibility).
Another solution is to edit the first image of the page and set the “Alternative Text” attribute. That attribute must be read as if you’d explain the image to a blind person as concisely as possible.
I don’t know how you inserted the images in your pages, but if you did it the “WordPress way,” the alternative texts should be implemented automatically. Otherwise, you should edit the page and reinsert the image.
Please note that it can take some time for Google to interpret the changes you make.