ENEMY WITHIN!
Stuart Burns is a sysadmin for a Fortune 500 enterprise based in that London.
Any sysadmin knows that sinking Monday morning feeling when you get to work and several hosts are misbehaving. It happened to me last week with several Docker hosts. Systemctl told me Docker was dead. But there were no obvious issues. The only thing that had happened was Docker got a minor upgrade from v25 to 26.