GXM box devices normally come in three configurations with a low-end device having internal PHY ethernet and the mid/high-end device having extneral PHY ethernet. The Q201 device-tree is for internal PHY only so if that doesn't work try the Q200 which has external PHY. If neither of those work you'll need to try other GXM device-trees. TL/DR .. supporting "board" devices is simple, but "box" devices are always a lottery.
NB: If the WiFi works, SSH in and share the URL from "dmesg | paste" .. maybe we can see more.