TouchOSC Erratic Faders


I have an iPad mini 2 running TouchOSC connected to my HedgeHog4X. I am using a custom OSC template with 6 faders associated with the first 6 Front Panel Faders (1 thru 6) on my Hog that work perfectly well.
Yesterday I tried a new TouchOSC layout that pointed the faders at the second bank of faders (11 thru 16) in the hope that they can be altered independently by another operator and without using up real estate.
Although the same layout works perfectly with Faders 1 >6, I get very erratic feedback from the console on faders 11 > 16.

Any ideas?