Comment by MattIPv4

Status page currently says the only issue is notification delays, but I have been getting a lot of Unicorn pages while trying to access PRs.

Edit: Looks like they've got a status page up now for PRs, separate from the earlier notifications one: https://www.githubstatus.com/incidents/smf24rvl67v9

Edit: Now acknowledging issues across GitHub as a whole, not just PRs.