Hello, I've tried every guide there was (the normal ones) and nothing worked; router acquires the .bin file, after some time it restarts, and it acts as a switch again. The device is TP-LINK Archer C6v2 EU region, and it happened right while I was installing OpenWRT software onto it.
What exactly do you mean by
and it acts as a switch again
OpenWRT comes by default with Wi-Fi off, you need to access 192.168.1.1 and configure your Wi-Fi for it to work