You need to put it through a standby cycle after power cycling.I am surprised power-cycling didn't sort it out (assuming there was an aerial signal at the time).
The HD- and HDR-FOX acquire date/time setup from EPG data, and then there is a real-time clock in the front panel module for standby timer functions. Access to the TV Portal functions require the correct date otherwise the authentication handshake between the unit and the Humax servers fails.
I am surprised power-cycling didn't sort it out (assuming there was an aerial signal at the time).
Things Every... (click) section 6
https://hummy.tv/forum/threads/hd-fox-t2-no-system-clock-without-aerial-feed-tv-portal-problem.707/