I don’t believe that there is any problem with your server; you have the latest version of archlinux-keyring (for the stable channel). It has been a while since the last stable channel update, so hopefully a new update will arrive in the near future. Even without that though, my understanding was that the archlinux-keyring-wkd-sync.service should help keep Arch keys up to date. Can you try running it manually?
sudo archlinux-keyring-wkd-sync