If the cab had been dropped or took a static or electric shock the display can go blank or show bad data.
If the track power and cab bus are bundled together right next to each other that could be generating crosstalk and bad data. Move them away from each other a few inches.
If the cab bus has several items on it, (UTP panels, throttles, AIU, etc.) or is very long, it might need supplemental power injected via the jack on the back of a UTP panel. We suggest for every 30 feet or every 4th device on the cab bus you add additional power to the cab bus. read this: Cab Bus Device Current Draw And Capacity
If it is a wireless cab, plug in the cab see if the issue goes away, then change the batteries!
Bypass your layout cab bus wiring by plugging the cab directly into the command station. If it works normal, you have cab bus issues.