Higher WAN throughput to VMs on the same host

[networkwarrior]

I am running 2.4.4-RELEASE-p3 on ESXi 6.5.
The host has an i7 4790 + 24 GB of memory
pfSense VM has 4 vcpu and 8 GB of memory allocated to it
There is only 1 other VM running at the moment. It is a DC with 2 vcpu and 4 GB of memory allocated to it.
My Internet connection is 1 Gbps down, 25 Mbps up.

From the DC, I get the full gigabit throughput during speed tests.
From other computers on my LAN, I get around 250 Mbps.
I am using a Cisco SG350 switch. All ports are synced up at gigabit.
iPerf testing from LAN devices to the DC (crosses the pfSense router across 2 different vlans/subnets), I get full duplex, gigabit throughput. If I connect a computer directly to the LAN port on the VM host, I still only get around 250 Mbps of throughput. I am running Snort, which I have disabled during testing, with no change. VMware tools is installed on the firewall.

Any ideas? During speed tests, the VM's memory and CPU utilization is very low. It doesn't look like a hardware limitation.
The nic I am using is an Intel EXPI9402PT 10/100/1000Mbps PCI-Express PRO/1000 PT Dual Port Server Adapter