Why won't my gbox mx2 connect to wifi?

[AC Question]

All of a sudden, my matricom gBox mx2 stopped connecting to wifi. I've checked the date and time, reset the modem, "forgot" the network and then re-entered the password, tried a static IP... Nothing is working. Every time I try to connect, I get an authentication failed message. All other devices in the home are working with wifi.
Can anyone help me out here? I really want to avoid hard resetting my box.
Thanks in advance.