LAUNCHXL-CC2650: adcbufcontinuous example in TI RTOS for CC2650 2.21.00.06 doesn't work correct

I test adcbufcontinuous example in TI RTOS for CC2650 2.21.00.06 on LAUNCHXL-CC2650 and find the UART always output values like the followings. No matter I connect DIO_23 to GND or 3.3V.

Buffer 1547 finished:
3348640,3346544,3347600,3348640,3346544,3347600,3346544,3347600,3347600,3347600,3346544,3347600,3345488,3347600,3347600,3346544,3348640,3345488,3347600,3348640,3346544,3347600,3346544,3348640,3347600,3346544,3346544,3347600,3345488,3347600,3346544,3347600,3347600,3346544,3346544,3345488,3346544,3345488,3346544,3345488,3346544,3346544,3346544,3348640,3346544,3346544,3349696,3345488,3345488,3347600,3345488,3346544,3345488,3346544,3346544,3348640,3347600,3346544,3346544,3344448,3347600,3347600,3345488,3345488,3346544,3346544,3346544,3347600,3348640,3347600,3347600,3347600,3347600,3345488,3347600,3345488,3347600,3345488,3347600,3345488,3345488,3347600,3347600,3345488,3348640,3346544,3347600,3347600,3347600,3347600,3347600,3346544,3346544,3346544,3347600,3345488,3346544,3345488,3347600,3347600,

I cross test adcbufcontinuous example in simplelink_cc2640r2_sdk_2_30_00_28 on LAUNCHXL-CC2640R2F and I can see UART outputs 0 when I connect DIO_23 to GND and see 3135/3292992(Raw Buffer/Microvolts) when I connected DIO_23 to 3.3V.

So, what's wrong with the adcbufcontinuous example in TI RTOS for CC2650 2.21.00.06? How can I fix it?