I don't seem to be able to connect to zammad-01 at all.
We increased the size of it over the weekend, which maybe we should have done from the start. Typically we start small and scale the instances as needed, but in this environment where scaling is not as simple or quick, that was a bad plan.
There was also an issue with our minimal initramfs as this is the first time we've run on an EFI host, and you need vfat to be in there otherwise /boot cannot mount (our workaround here was to add nofail to fstab for that mount). I mention this in case that issue was bigger than I anticipated and maybe it gives a context clue if it's crashed in some way.
But the host seems to be offline entirely now. I have no access to any out-of-band tools so I will leave this ticket here, it's not something I can investigate.