The canonical link in https://commits.webkit.org/251850@main says https://commits.webkit.org/251851@main, which is off by one.
<rdar://problem/96075689>
Also PRs are landing with the wrong canonical links: https://github.com/WebKit/WebKit/pull/1717
The canonical link is right, commits.webkit.org was off-by-one incorrectly redirecting. That's a less serious problem than Commit-Queue getting this wrong (because fixing it doesn't require force-pushing), but it's still a big issue.
I haven't seen this issue in a few months. I made some changes to how we manage our identifier cache early this year (257251@main and 257145@main) that might have addressed the problem