I managed to solve this. The firmware seemed to be US version (and the newest at Tplink support site). This was very confusing because I am living in Finland and has a second-hand device. I managed...

Hi, I have an Archer C7 v2. Firmware Version: 3.15.3 Build 180114 Rel.39265n Hardware Version: Archer C7 v2 00000000 I cannot upgrade the firmware. I have tried every EU firmware bin-file that can be...