AC/heat not blowing using fan speed control

The front AC/heat fan speed controls on my SUV (with automatic controls) do not work/operate.

I can feel some air coming out, but the speed will not change up or down.

The rear temperature and fan speed both work, just not in the front.

I have read about problems with the blend door actuators, but how do I know which one may be bad and needs changing?

I have checked fuses and fuse blocks. Also did the reset procedure of removing the battery terminal for five minutes and starting the truck without touching controls for at least one minute. Nothing has worked thus far.