Last year I wrote Bing and DuckDuckGo removed my business web site describing how https://underpassapp.com had been removed from Microsoft Bing search results, and thereby also from DuckDuckGo search results, since DDG relies on Bing. As described by my friend Jesse Squires in the blog post My website disappeared from Bing and DuckDuckGo, Part 2, that problem was actually solved last year for both of our sites. However, today I read a blog post by Dave Rupert, I'm Shadow Banned by DuckDuckGo (and Bing), which inspired me to check the search results again for my own site. Sure enough, https://underpassapp.com is now missing again from both Bing and DuckDuckGo!
It's still in Google though.
My personal site https://lapcatsoftware.com was never removed from Bing or DuckDuckGo. Only my business site is missing.
This situation is absurd. Microsoft needs to get its act together and stop deindexing web sites for no reason. (Here's yet another example: Microsoft Bing – site gone from SERP overnight!) Meanwhile, DuckDuckGo needs to get its act together and build its own independent search engine (not to mention its own advertising sales) instead of relying on highly fallible results from Bing.
Today my site is back in Bing and DuckDuckGo! I don't know why. Maybe it was random? Maybe someone at Microsoft saw my blog post? I did "ping" someone I know at Microsoft, but I didn't hear back from that person. It appears that https://daverupert.com/ is still missing from Bing and DuckDuckGo, however, so the problem isn't entirely solved yet.