Hello, I have two ISP's, the first one is the fastest and is connected to WAN(1) , the second one is slower and I have it as a backup.

The connections are:

Fast ISP modem/ router ---> WAN1

Slow IPS modem/router---> WAN/LAN

Wireless Router (AP) ----> LAN4

Both are configured as Dynamic IP, because none of the ISPs allow bridge mode.

The ER605 is given 192.168.0.1

Fast ISP router has 192.168.2.1

Slow ISP router has 192.168.1.254

Both ISPs have the firewall disabled and have a static IP address assigned to the ER605 mac address. Also DMZ enabled to the er605. 

The first ISP works flawlessly, the problem is within the second ISP. Whenever the physical connection of WAN is removed, the failover function does the job, but when it fails for example, because an ISP issue, the fail over wont work and the internet connection is lost in general. Both ISPs connection seems to be connected correctly in the network menu, but in the online detection, the second ISP always appears as Offline. If I change that to "always online" it still won't connect successfully. Also tried with manual configuration 8.8.8.8 and its the same problem.

If my PC is connected with an ethernet cable or directly into the wifi network of any of the ISPs routers, the internet connection is working without any issues.