@Yos 

For your first question, you can use Policy Routing function to make the traffic pass only single WAN. It can work with load balance at the same time. It's based on IP address and TCP/UDP port. You can refer to the FAQ. https://www.tp-link.com/us/support/faq/2134/

For your second question, cannot make sure what firwall feature would cause this issue. Maybe you can try to disable each option one by one.

@Andone Yaaaas...I like your answer...thanks a lot

@Andone 

Currently my network is as follow:

Level 1: 2x WAN

Level 2: Load Balancer

Level 3: 2x Wireless Router

Level 4: Phones, TVs, PCs

The link you provide can manage the ip of LAN (level 3) connected to Load Balance.

Can you guide me how to manage level 4?

@Andone 

My devices connect through Wireless Routers before R470T+.

2 Modem >> Load Balance >> 2 Wireless Router >> Devices

how to make Devices IP showed up on R470T+ ?

Yes, I want to control certain device traffic. Not all traffic.

Sorry I am New in Network config.

Thanks

@Andone 

Already set the AP mode, then all worked very nicely.

Scenario.....I want to set :

IP_GROUP_1 (certain ip adresses) to priority WAN-1

IP_GROUP_2 (all other than IP_GROUP_1 above, which include the future to be assigned ip) to priority WAN-2

How to config the routing priority in easy way?

Kindly guide.

@Yos 

I think you need to set up two items for policy routing.

1. Make IP_GROUP_1 go to WAN1. So source IP of this item should be IP_GROUP_1, destination and service type is ALL. Choose interface as WAN1. Make the rule ID as 1 to make it has the highest priority.

2. Make IP_GROUP_2 go to WAN2. I think IP_GROUP_2 means all IP addresses just not include IP_GROUP_1. So for the second item, set up source IP as ALL IP.  Destination and service type is ALL. Choose interface as WAN2. Because IP_GROUP_1 data will match the first item, so it will not match the second item. So IP_GROUP_1 will go to WAN1. Other data will match the second item, then go to WAN2.