Just picked up this jointer used in very good condition. I’ve never had a jointer with a lever to move the bed.
I can make rapid gross adjustments by pulling up and down but turning the shaft does nothing. The manual states turning the worm shaft will make “fine adjustments “ to the infeed bed hight. I even bypassed the cheap plastic knob and put a wrench on it without forcing anything…still nothing.

Is my interpretation correct? If so, is it likely something is is stripped or not engaging?

I feel like the worm shaft and its plastic handle are not even equipped to create enough torque to move the bed. All that happens is the shaft goes up or down as it is turned…not the bed,