The problem is that "MXQ pro 4k" is not a specific box, but more of a generic label that is used by multiple manufacturers and sellers. The box I own (see my signature) works fine with the generic gxbb_p200_1G_100M device tree, but yours is most likely newer and uses a completely different board and wlan chipset. Did you try one of the "realtek" device trees?
You can open the box and take a picture of the PCB. Then we might be able to help you further.
Not being able to switch a powered off box with the remote is an issue many boxes have. Current understanding is that in order for this to work, the manufacturer needs to make sure that the u-boot bootloader correctly recognizes the remote signal. This takes extra work, so with the cheap boxes, it often is neglected. My MXQ Pro 4k simply switches the hdmi output in its android firmware when I push the button.