Expression pedal travel reading incorrectly

[themetallikid]

So I've had no issues with my Helix other than some weird Expression pedal reading issues.  Meaning with my Mission Engineering one it will sometimes only read 0-98/99%, making the auto-engage needing to be set at 97%.  Its pretty much full travel so I've lived with it.  

Because I really only use one pedal at a time in most of my presets I decided to ditch my ME pedal and use the onboard expression pedal.  Its worked great the last 2 weeks while I tweak and make sure everything works right.  Spent a good deal yesterday redoing some EQ things to make sure they are even, tweaking some wah settings, and its been working perfect 0-100%, so I've been setting my auto-engage to 98% give that extra bit of space.  

Of course last night at the show, I get through 3/4 of our set, and we rip into Crazy Train (we have a 2nd guitar player, which made this even worse).  We start playing the main F# riff and something doesnt sound right....we chug along into the first verse and something is clearly not in tune.  I quick check my guitar, everything in tune....I look at our other player, and he checks his by ear when I stop playing and it sounds fine.  I start playing again and something is off....come to find out, I have a Whammy/Pitch block, at the beginning of the chain....the on-board pedal was only reading 0-91%.  So it was pitch shifting down whatever 9% of the -18 setting I had it for.  I stopped the song in order to find that out, I deleted the block and we fired it up again....

Next song Enter Sandman (wah pedal used of course for the leads)....I step on my rhythm snapshot to check if I have the same issue there and sure enough, Wah was stuck on at 91%.  Had to quickly edit the auto engage to 90% to overcome it.  

 

What an annoying let down.  I remember someone saying they had a pet hair that got in there and was causing issues with the sensor.  I'll be bringing my ME pedal tonight as I do not like dealing with gear issues like that, especially right in the middle of the performance.  

 

Anything else I should look at so this doesnt happen again?