I had an agency client in 2021 with an identical issue. In that case, the agency was able to contact a support representative for Bing's Webmaster Tools that provided a little more info, and some further investigation on my end revealed that the Bing crawler was doing something idiotic that was triggering http error response codes from the application, and the crawler took that to mean that the site was broken or down.

It was an intersection of multiple stupid things, not maliciousness.