It's been a while as I remember it, you have 14 characters to split between the names of the zones and the names of the channels.
So, you can allocate three characters to the zone, and 11 to the channels. Or you can allocate one to the zone names and 13 for channel names. Any combination, but it's universal for everything in the radio. If you pick 2 characters (for example) as the zone name length, then ALL zones will have only 2 characters available for zone names, and 12 characters will be available for all channels.
Once you've got that in hand, see if you're having other problems and if so, we'll look at it.