You use the web editor to change Ctrl Port settings, such as TRS MIDI or expression pedal settings, but it reverts to the previous setting when the pedal is unplugged.
You need to scroll down to the bottom of the page and click the Save button. The pedal's right LED should blink green and the control port configuration will be saved.
You need to take this extra step because the expression pedal destinations and min/max range can be saved globally or in a preset. The control port mode is global.