@SlowUsbPort 

https://www.tp-link.com/us/support/faq/2133/

 

Primary: WAN1 

Backup: WAN2

1 fails, then switch to 2. If 1 is online, switch from 2 to 1

that's why there is another option "online detection". This tests the connection. 

It's not possible to use 1&2 together doing load balance and backup together. Quote from the UG: 

With Link Backup function, the router will switch all the new sessions from dropped line automatically to another to keep an always on-line network.

(https://static.tp-link.com/2018/201811/20181109/1910012492_TL-R480T470T_UG.pdf)

 

WAN2 trouble you mentioned, it is more like something wrong with the connection on WAN2. it is not an issue with the router. The issue with the ISP or signal 

What device do I need to " It's not possible to use 1&2 together doing load balance and backup together." Why cant I load balance and backup together? Load balance when both are online, and backup/failover if one or the other is not working ?

@SlowUsbPort 

Premise of the Link backup is Load Balance. But, read the User Guide. 

Sessions are not forwarded to the WAN2 if Primary is online, which means the Load Balance is not working because of link backup is using WAN2 as backup only. 

@John1234 

 

But I want it to do both

 

@SlowUsbPort 

https://community.tp-link.com/en/business/forum/topic/511086

I am repeating what the User Guide says. And I am not dev. You wanna do that and you can refer to the workaround. Not "I want". Things don't always work as you expected.

Well , the point of my statement is I need a device that does function this way. " It doesn't work the way you expected" means I should take my money and purchase a different device that does work the way I expect. Sad that this device can't perform the most commonsense function. Maybe I will try Pfsense

@SlowUsbPort 

The link I posted in the last reply was some kind of workaround.