I finally managed to solve the problem, my box can connect to wifi with that new 2734C chip. Thanks to @jock for directing my attention to the nvram file, I was wrong, dtb was not needed to solve it. However, Google didn't help with the solution (I don't even understand how it could have helped), but I contacted the Chinese manufacturer of the box and they helped. I have attached the correct nvram file, the content of which I overwrote the brcm/brcmfmac4334-sdio.rockchip,rk3318-box.txt file that comes with the current image. I recommend that you integrate it into the kernel, because the current kernel does not, or at least does not, support this widely used wireless chip.
nvram_2734c.txt
Swithin Mutaasa Serwadda reacted to paradigman in CSC Armbian for RK3318/RK3328 TV box boards