I never thought of moving the highlight to the channel number, since it appears to default to the horizontal line representing the programming.
(The listings are all blank, which I assume is because I’m not subscribed to the guide service.)
Even without the guide subscription, I think you should be getting 24 hours of guide in the grid. If you’re not, it’s probably because your zip code is set wrong and the device can’t match up the RF channels it’s detecting with the actual stations.