Need help with Using Property Control to Control X Axis: Axis becomes fixed after changing Continuous Scale to Categorical Scale


I'm using document property control to control X Axis of a combination chart as below. And X axis is continuous as default with this.

If I change X Axis to Categorical Scale, the X axis would not be referring to the Property Control anymore, instead, X Axis would be fixed and I could not change it with the Property Control on the right.

How could I make X Axis categorical all the time with the Property Control still functioning? Thanks.

(1) Answer