Google has been changing and testing the interface for its sitelinks for as long as I can remember. Well, here is another test, for the Google Ads version of the sitelinks, where Google is displaying them as a vertical list view.
This screenshot below is from Andrea Cruz as she shared with me on Twitter (you can click to enlarge):
This is what I see:
Andrea wrote "Google Ads showing sitelinks in a vertical type formatting." No surprise there and I think Google has been on and off testing this for some time...
Forum discussion at Twitter.