@Marvin_S thanks for the answer. 1- with firmware C6(EU)_V4_1.13.6 installed , I've done a factory reset . the result has been the same : loopback doesn't work. 2- you suggest downgrading firmware...

Since I updated firmware to Archer C6(EU)_V4_1.13.6 Build 240430 version , the loopback doesnt work well. I can not access to my home server using the ddns address. Sometimes it works during some...