My network reset all connection periodly

hi, Everyone:
I have ten machines of the same type, and same network. But two of them have some problems mining, they reset all the connections and resync the ChainDB, and this cause a lot of disk io and network traffic, and more stop of mining for hours. The message in log is as below:
Update predecessor error: neighbor list is empty

2021/08/24 19:24:57.861496 ^[[0;32m[INFO ]^[[m GID 2692, Connect to random neighbor at key d2d5127c59004c0757c79489bb3526d3dd049e21680230aa447b090947b9fb4a error: trying to connect to self

I am not sure if it’s a failures of the network, But the nknd restarts itself and working correctly later on.
I wonder is there anyone else has the same problems and can gives me some advices. Appreciated for any informations.

HI zephyr,
Did you keep those failure machine?
If you don’t have important asset in these machine, maybe we can ssh into it and check it out?

I am sorry I reinstalled those machines… May be it’s a problem of my systems.
I will let you know the next time I found it agina. Tks