Icmp dropped on KVM/Qemu - pfsense 2.4.2 (amd64)

[pakito]

Dears,

my hypervisor (Debian 9.2) has 2 NIC Broadcom
I had put those NIC in brige 0 and 1

my vm has 2 virtio interface bridged to hoster
the first interface has static ipv4 address (WAN)
the second use a Vlan (LAN)

The traffic is natted by Wan nic.

When I send rapidely 1000 icmp packets to internet, I loose ~ 4 - 6 packets.
I dont have errors on interface.
When I sniff from hypervisor, I saw icmp packet enter to vnet nic but I dont see outgoing on other vnet.
I can saw the state from incoming but I dont saw the outgoing state like others ping.
the state table is not full
Disable hardware checksum offload is checked
Disable hardware TCP segmentation offload  is checked
Disable hardware large receive offload  is checked

I can reproduce this problem with pfsense 2.3.1 to 2.4.2, with em1000 or virtio interface

Does anybody can help me ?
I've been pulling my hair for two days

THx

Pedro