First, the only thing you really have to do is to set “Use expression pedal, Aux switch, or both” to expression pedal. (Or “both”, if you’re using switches + pedal). This is under “general settings” in the “pedal” menu of the H9 control software.

Then the tip, ring, tip plus ring assigment has nothing to do with the expression pedal. It is for the auxiliary switches.

LA