Yes, not so minor detail. As I remember, the EV5 stock uses ring as hot, tip as wiper, shield as ground.  So if I remembered correctly, it should work, but if it's been modded you can take it apart and swap black and red wires to make tip the wiper.  On mine I just installed a jack long ago and quickly resolder the wires for whatever I happen to be using, whether TRS sleeve hot, TRS Tip hot, or  TS.  Unfortunately there is no standard wiring for expression pedals.

 Now it's just wired as a resistive load.. TIP = Wiper, Ring = Ground.  It's worked this way for the last few pieces of gear I've used so I've left it alone and forgot about all the changes I had to do prior

So you might want to check inside if yours is miswired, if so, I would recommend reversing the black/red wires first..  Or what had been mentioned about bridging across tip and ring would work too, but I think it would be easier to just swap them.

Having said all that, if yours is working for all settings but one, and you can see the sweep from 00 to 99 or 100,  I would guess the pedal is wired right and something else is going on.