I bought the VR600 2 years back and until recently everything was fine. After a sudden power outage, the router stopped serving IPs from my DHCP server.

My setup is as follows:

I have a generic ZTE router that my ISP gave me since I need it to use my landline phone in order to have a telephone connection. I use it ad my DHCP server and I connected my VR600 as a WiFi AP and the build-in switch to connect 3 other devices.

The VR600 has a static IP outside the DHCP range and connects directly to the main router via Ethernet. The DHCP is disabled.

Now the most peculiar thing happens. If I try to connect my phone to the WiFi for example I get stuck at "Obtaining IP address..." and never gets IP. If while I do that disconnect and reconnect the Ethernet cable of my main router (where the DHCP is working) then I immediately get IP. If I disconnect the phone from the WiFi and try to reconnect it I get the same problem and I have to do it again. The LAN connection doesn't seem to be affected though and I don't know why it does that. I flashed to the latest firmware "Archer_VR600V2_0.3.0_0.9.1_up_boot(200226)_2020-02-27_08.58.18.bin" but doesn't seem to fix the issue.