Confirmed in access logs no federation traffic from .world is coming in.
And apparently piefed.social is also not receiving federation: https://piefed.social/c/piefed_help/p/1484033/not-federating-with-from-lemmy-world-how-to-report
Resolved: Thanks, Mr. Kaplan!
Indeed, piefed.social also seems to be behind: https://grafana.lem.rocks/d/bdid38k9p0t1cf/federation-health-single-instance-overview?orgId=1&var-instance=piefed.social&var-remote_instance=lemmy.world