DUAL WAN How to block single IP from access to WAN2

[toxsickcity]

Hi,

i am looking for a little guidance with blocking traffic to a particular pc on my home network
I have tried a few things and am totally confused as the things I have tried i think should have worked :(

anyways I will try best explain my setup,

I have a Laptop with 2x USB Ethernet Ports and an Inbuilt one,
the Inbuilt one is the LAN connection to my computers, the USBs are both WAN1 and WAN2 which pfsense convert into a load balanced internet for me to enjoy.

anyways one of the machines on the network (192.168.0.51) Hyper-v virtual machine is a downloader/uploader and my WAN2 is very HIGH SPEED but limited to XX GB/Month.
I have added the ip addy to a rule in firewall and traffic is still being used on WAN2 from that computer.

So Under Firewall/Rules I have Floating / WAN1 / LAN / WAN2
under LAN I have a ALLOW rule setup by default which is set to LoadBalance gateway to allow any traffic to anywhere.. and think this is what my issue is!
I am scared to disable this as once I was locked out haha!!

anyways things Ive tried

I have tried adding a rule with source being 192.168.0.51 and destination to ANY
I have tried another rule with the Destination being 192.168.0.51 and source set to ANY
I have than tried adding the above rule in WAN1, LAN and WAN2.. sections..
I have also gone to advanced inside the rule and setting the gateway to LOAD Balance and tried also on WAN2

I am also confused about the order top to bottom..

I am just a little lost i guess and hope someone can suggest the correct way to properly firewall traffic from that local PC.

Cheers
Shaun