Sites are delisted from Bing & DDG as a result of negative SEO attacks. I've experienced this multiple times and responded to a couple of threads on HN about it.

The attacker doesn't care about your Bing listing, it's an unintended coincidence of an attempt to get your site deindexed from Google search that doesn't work.

Google ignore bad links to your site, Bing don't.

After two years I can confidently conclude that MS have done a great job of hiding this 'defect' and virtually nothing regarding the root cause.

In my experience, the sites come back on their own eventually but with a lot of really weird URLs being indexed first (a sure sign of the original attack).

Very good article -- I am having the exact same issues (I run a lightweight writing site with original writing and no ads). One thing that caught my attention is the timing. Bing blacklisted my domain from web search results on January 14 after I had no issue with them for 2.5 years (interestingly, I wasn't fully blacklisted for image results but that doesn't help me much). The rest of your article, from lack of support and information to Bing Webmaster only identifying minor SEO issues has been my experience. My site has no indexing issues with Google, Yandex, Brave, or Mojeek... so whatever it is is Bing-specific. I agree with your point on DDG too. I also had more DDG traffic than Bing traffic, and losing a smaller number of Ecosia, Qwant, and Yahoo referrals is also unfortunate. Many people do not realize how many of the alternative search tools rely on Bing's index.

Whatever is causing it -- I hope it is fixed soon.

Try to contact Mikhail (Bing CTO, @MParakhin) or Michael Schechter (Bing Growth VP) on Twitter. They are very helpful. Or Bing Head of Product, Jordi, which is very helpful on his email as well, jordir at Microsoft dot com.

That might have been more useful as a title (shortened, obviously, but longer than the two words that mean nothing together as it is now)