It seems to be locked into 2wd and can't shift when buttons are pushed.
I get no amber indicator lamps on my shifter buttons. won't shift to 4wd. on 2004 Chevrolet Silverado 1500
check your fuse, relay, and connectors at shift button or transfer case and actuator . No lights indicate a loss of power at the shift button terminal...
maybe the actuator or fuse is not working.