Automatic restart of esxi6.7 host,How to find out why?

Hi,

I have 4 new servers(HPE ProLiant DL560 Gen10)(Intel(R) Xeon(R) Gold 5118 CPU @ 2.30GHz).

I installed esxi6.7 for them.

Then they restart at irregular intervals.

The first server，about restart 2-3 times a day.

Second server，about restart 15-20 times a day.

Third server，about restart 4-6 times a day.

Fourth server，about restart 1-2 times a day.

There is no warning before restarting.

Every time it's a sudden restart.

The day before yesterday, I installed centos7 on the second servers above, and now it has been running normally for more than 2 days.

So it should not be the problem of the server itself.

How can I find out why they are restarted when they install esxi6.7?

Thanks.