amazon pop-up shortcut window removal

My wife gets this window, headed "Skip to," once signed in to her Amazon UK account on her MacBook Air. There are no browser extensions and I've tried every suggestion on removing it I can find, without success. It looks like this:

I've even spoke to Amazon, who sent an email with instructions, but they were irrelevant, in that I do not have the extensions and they recommended blocking Google website, which I could not to, although I tried. Has anyone had this intrusive software and removed it, please?