stock 08 sl 6 cd changer heat unit?

[viet510racer]

before ive noticed that my stereo shows the number that the radio station is set to such as 1, 2, 3, etc. and now it doesnt show it on all the stations thats setted. i do noticed that station 1 shows but 2, 3 doesnt. so if i were to press 1 it will turn to that station but if i press 2 or 3 it turns to the station but doesnt show the number 2 or 3 on the left side in the display. can someone tell me whats wrong and how to fix it? sorry if this is kinda confusing