Why is vm shutting down by itself?

Question

Xen

There is a hypervisor based on Xen
A pool of 5 physical servers.
~50 vm

has been strange lately.
today one of the vm suddenly shut down.
there is nothing in the vm logs. the records just break. in the hypervisor logs, there was also nothing related to this vm
, there was no load on the vm. according to monitoring, everything is as usual, there are no jumps or excesses

a couple of weeks ago, it was the same with another vm.