Symptoms:

– Ping works with no problem,  from LAN to LAN,
from WAN to WAN and any cross-subnet combination with the correct NAT/gateway rules.
– TCP connections work in one way or between specific hosts, but in one direction to WAN or from WAN they don’t work,

Slow traffic (~5.67 Kbps)  !!!!
– UDP  work sometimes,

First :  Login  Host machine,   SERVER which is Main

Second: Open pfsense
Disable the hardware checksum offload. 

References

https://doc.pfsense.org/index.php/VirtIO_Driver_Support
https://doc.pfsense.org/index.php/Limiters
https://turbofuture.com/computers/How-to-Configure-Deep-Packet-Inspection-Using-pfSense
https://www.reddit.com/r/PFSENSE/comments/45k0n5/pfsense_slow_wan_throughput/