Router: Proxmox with OPNsense virtualized
Switch: SG2428P

Situation: After configuring a VLAN interface and then enabling that VLAN interface on the above switch, I can see and experience frequent packet loss across my entire network (not just the VLAN that was enabled)

Details:

• Proxmox host has an intel 4x 1GB NIC, one to WAN, one to LAN (switch port).

• Personal Laptop configured on switch port 12 (example)

• OPNsense Router virtualized on Proxmox. LAN gateway is 10.0.0.1

• OPNsense Router has VLAN Gateway configured as 10.0.201.1/24, DHCP range of 10.0.201.20-10.0.201.254

• OPNsense VLAN 201 is configured as 10.0.201.1/24, VLAN 201. DHCP server disabled, Legal DHCP server 10.0.0.1, DHCP L2 relay enabled.

• On Switch > Config > Configure VLAN 201 - static IP 10.0.201.2, mask 255.255.255.0, DHCP Relay 10.0.0.1. Apply.

• On Switch > Config > VLAN Interface - Enable VLAN 201.

• On Switch > Ports > Port 12 - Profile VLAN 201. Apply.

Once I assign a port to the VLAN I can start to see that pings and network connectivity drop frequently. Easily for 1-2 seconds every 30 seconds. This is observed across desktops, laptops, and Wi-Fi devices as well.

If I do not have a VLAN profile assigned to a port (other than using "All") then I do not experience this packet loss at all.

Is this a misconfiguration that I have made on the switch, OPNsense, or a hardware issue with the switch?