Looks like some sort of display error. There's no channel number being displayed for that frequency. For us OCD types, pressing 'D' (discard/forget system info) causes all of that channel data to be rebuilt/redisplayed.
I would check to see if that is a licensed freq for that system first. If so I will make a guess and say the channel was 'busied out' or otherwise disabled. Just a guess of course.