Because if you put the headlines (in quotes) from two of his recent articles into Bring, e.g. either "Megan Smith explaining the General Magic prototyping process" or "Denialists, Alarmists, and Doomists", both point as their first result to a URL starting with "https://www.scien.cx" which seems to be the spam site with a copy of each article. (The URL isn't loading right now, however, when I try to visit.)
How to fix it really depends on what techniques they're using to mirror your site, of which there are many.
Example search and resulting URL:
https://www.bing.com/search?q=%22Megan+Smith+explaining+the+...
https://www.scien.cx/2022/12/25/megan-smith-explaining-the-g...
Compare with Google getting it right:
https://www.google.com/search?q=%22Megan+Smith+explaining+th...
https://daverupert.com/2022/12/megan-smith-general-magic-pro...