So I encountered an weird feature to me, in that if the traffic goes though the firewall to enter another VLAN, it will have it' source address NATed to the interface in question.
Eg traffic from 10.0.105.0/24, will get it's source address NATed when it's traversing firewall to go to another VLAN on 172.16.9.0/24. I want it to keep the source address instead... It also seems to be the rule " let out anything from firewall host itself" which I have no control over?
Okay, user error. It would help to remember to check nat outbound rules before making a topic about it.