Boxes with 'x' in the corner, but with no content, tend to occur when your browser has blocked something that the website owner wants you to see (such as an ad or a notice about cookies) but not blocked the box which should contain the message. (As you're only seeing it on AB, it could well be something like AB's 'we value your privacy' messages, which have a nasty habit of turning up on every page with some browsers). As the problem really lies with the code on AB's website, I doubt that there's a way that you can configure Chrome to prevent it happening.
Might I suggest that you try using Slimjet instead of Chrome? It's built around the same basic (Chromium) browser that powers both Chrome and the latest version of Microsoft Edge but it doesn't keep sharing all of your information with Google and, because it blocks ads by default, is faster than Chrome:
https://www.slimjet.com/