VLAN for a Failover Modem and one of my Subnet networks (for camers)

[ahole4sure]

So I have a 4 port pfsense box. All the physical ports are full. I wanted to add an ATT Modem for Failover. (I do have a static IP but I would like to be able to set it up as DHCP - I have another setup where DHCP works but it is not connected to a VLAN) (See diagram)

I have attached a pic of my TP-link switch setup - Port 1 (of the switch) is to be the trunk, Port 2 is to be the connection to the ATT Modem (WAN), and Port 3 will go to my existing Camera subnet.

My issues have been that I just can't seem to get the ATT modem to give the DHCP info to the pFsense VLAN that I have created.

Another issue - the parent interface is a LAN with 192.168.3.0/24 subnet. I have the switch set to 192.168.3.3 and it is accesible. I have set the ATT modem to be 192.168.3.2 but it is not accesible from my main LAN. (unlike the switch which is accesible AND another test environment where the ATT modem is accesible but it is connected via a direct physical interface with DHCP - see differnces in interface status page)

Any thoughts on getting dhcp going to the pfsense form ATT over VLAN to work?
And making 192.168.3.3 modem connected via VLAN visible over my other networks?