There has been a glitch in Hetzner cloud about 3 hours ago that has restarted all my vaults, same for @happybeing’s vault. Which means that 10 vaults out of 19 were restarted at once.
The network seems to have absorbed the impact: I have tested some of the safe sites listed here and they still work.
Sorry, they didn’t restart. A docker command at the service level made me believe that. But when I inspect each vault individually, no such event happened.