My 4WD system has lights to indicate whether you are in RWD, AWD or locked in to 4WD. There is a light for each wheel and a light showing the transfer case is locked in 4WD. The indicator lights come on when the vehicle is started but the right rear wheel indicator turns off soon after the vehicle starts moving, but should stay on as the others do. Is this a wheel sensor malfunction or potentially a deeper issue with the ABS system?

Is this the one you are talking about, only on the bottom? That's just your led not working properly. I've taken my gauge cluster apart to see if I could fix it, but the leds are soldered in. They are very small.