I am on a very similar setup as you are (Intel Celeron N5105 machine with 4*Intel i226-V 2.5G NICs, proxmox, 6.1.0-1-pve kernel, pfsense 2.6.0) but somehow, I am facing slow network speeds on my pfsense vm (in use as my firewall):
- When I run iperf3 from a VM to Proxmox host, things are fast...