Proxmox VM randomly network unreachable

[TDex96]

Hi guys!

I have more than 10 Proxmox machines.
On these proxmox machines i have 2 routing server with Ubuntu 18.04 with high traffic. I whatched some urls with pingdom across the routing servers and randomly i received network error for the routing servers. I didn't find anything in syslog and other other logs. Before Proxmox we used simple KVM virtualization and didn't we met something like this. Is it possible to the problem is Proxmox?
Some other information:
We use Proxmox 5.4-3
My kernel log forthe Ububntu machine full of network disable, blocking states.

May 20 08:13:24 routing-02 kernel: [3704149.949892] device veth16230f6 entered promiscuous mode
May 20 08:13:24 routing-02 kernel: [3704149.949949] IPv6: ADDRCONF(NETDEV_UP): veth16230f6: link is not ready
May 20 08:13:24 routing-02 kernel: [3704149.949952] br-f5910cf2f4ff: port 3(veth16230f6) entered blocking state
May 20 08:13:24 routing-02 kernel: [3704149.949953] br-f5910cf2f4ff: port 3(veth16230f6) entered forwarding state
May 20 08:13:25 routing-02 kernel: [3704150.621756] br-f5910cf2f4ff: port 3(veth16230f6) entered disabled state
May 20 08:13:25 routing-02 kernel: [3704150.657916] eth0: renamed from vethd2c1019
May 20 08:13:25 routing-02 kernel: [3704150.685909] IPv6: ADDRCONF(NETDEV_CHANGE): veth16230f6: link becomes ready
May 20 08:13:25 routing-02 kernel: [3704150.685945] br-f5910cf2f4ff: port 3(veth16230f6) entered blocking state
May 20 08:13:25 routing-02 kernel: [3704150.685946] br-f5910cf2f4ff: port 3(veth16230f6) entered forwarding state

Have any idea?