Change your protocol to some other and try again (Stalker MAC/ID, XC Api or M3U Playlist).
Yesterday there was an update to the Z11, Firmware 11.2.9 and MYTVOnline 11.2.34 and that seems to have fixed the issue!
I haven't changed any settings, but now after the update the live channels are viewable..
Glad it seems to be fixed, but funny I was the only one reporting the issue. Also hate it when things just "fix themselves" without finding the cause.