GitHub appears to be having an issue where PRs are disappearing from search, but only search; if you know the PR #, you can still find it.
Now an incident: https://www.githubstatus.com/incidents/ql942tw29yl6
Tell HN: GitHub PRs disappearing but only from search
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Re: Tell HN: GitHub PRs disappearing but only from search
#2We discovered this at work when the number of PRs in our monorepo started dropping off a cliff. Caused quite a panic!
Re: Tell HN: GitHub PRs disappearing but only from search
#3The incident is now closed, yet the issue still persists.