Overdrive button not working

I bought a 2001 Xterra and the overdrive button on the side of the shifter doesn't seem to be working.

I am almost certain it is in overdrive as driving on the freeway at 60 it is turning about 2250 RPM which seems about right for that speed.

I guess I am wondering, is there any special procedure to get overdrive to turn off or any known issues regarding the button.

The light on the dash does work as it lights up when I first start the vehicle with all the others initially.