I posted this screen on another tread, but the cause is found, it is an interface error.
While testing the auxiliary loop, I kept getting this message: "Aux Input is active". However, the RIG manager window and the Kemper Head window were in zero position (no input). I did not understand. We spoke several times with the help line to finally find that ... one of them was below 0.1 but above 0.0
Here is a trap which may surprise. The Rig Manager button goes from 0.0 to 0.1 but the Head button allows an intermediate pisition. For this reason, the Loop effect is deactivated without the screen allowing to guess why.
Below is the normal (example) situation for the RM and the Screen when the Aux Input is active.
If one of the three is at 0.01 but not yet at 0.1, the loop is disabled but could show 0.0.