https://thejollyteapot.com/2022/10/28/something-is-rotten-in-the-state-of-bing-search
MS seems to have quit improving Bing a few years ago and has been content to milk it as a revenue source.
Seen a lot of these reports over the past 6 months or so, though they don't ever mention looking at server logs. Some are behind Cloudflare, and mention that Bing Webmaster Tools indicates crawling happening but no indication of the server seeing the request.
Anecdotally at Mojeek we've seen issues with Cloudflare and other WAF's, though probably a non-issue for Bingbot. Crawl a page behind CF one day and get a 200 and another day a 403. These blog posts tend to indicate 4xx responses to makes me wonder.
Also seen comments about it being a potential issue with sites that rank well on G and are subject to negative SEO of whatever sort. I've no idea whether Bing uses negative signals.