@Hari_V Check the AX90 specs. It utilizes 2 WAN ports.

@redovidiu Do you have other sonoff deices in your network ? If you do, is this the only one with problem connecting ? I would suggest to reset the router to factory default settings and configure...

@SimpleNeeds Go with the EU version. You can read the release notes for the version in question about bug fixes implemented.

@SimpleNeeds Try upgrading your router FW. It looks like outdated - from 2018. If your device is Archer C20 HW v5 then observe your region: EU FW is here. US FW is here. Update to the newest release...

@APmodeUser About the beta FW - that's a final resort if nothing other helps. C6 in AP mode with 1.3.6 official FW works fine when configured with Static IP and DHCP OFF. If you have network...

@APmodeUser What you can do is to check again ping results when connected by cable to C6 - ping your main router 192.168.2.254 and see if any packet loss (that's the last ping test you did). If there...