Turris Mox powers down

I’ve got a Mox A setup as a wireless access according to the instructions. Seems to work fine, red light flashes, I can use the access point to connect to the LAN and the internet via the main router (a Turris Omnia). However after about a week, the light turns off and the unit cannot be contacted, nor is it transmitting a signal. Unplugging and replugging makes it work again. I’ve got a POE module connected but am using the included wall wart. Hoping this is not a hardware problem, but simply some weird sleep condition…