Connected it to WiFi around 12 AM. All morning it flooded the AP log with prev auth failed as well. Some other stuff too in it. Since Zyxel still hasn't responded, I may have bought a new AP, well a router that can be used as an AP.

Their support is super slow, or doesn't care. Not everybody is a network engineer. Not to mention, I don't have access to the source code for the firmware, so if it is the AP's problem, I can't fix it. Could be a hardware problem for all I know.

Either way, I probably won't buy Zyxel again.