Mix switch on Devo 10

I just started to use the mix switch on my Devo 10 without success in the beginning. Now I am wondering if the Walkera QM was out of control or the previous owner changed this switch.

On my Devo the channel monitor displayed the following:

Switch position MIX0:
MIX0 = -100
MIX1 = -100
MIX2 = 100
Which should be the correct assignment for the MIX2 normally.

I just turned the switch in the Tx and now is ok. But can anybody confirm that for MIX0 switch position the channel monitor will display without turning the switch itself:
MIX0 = 100
MIX1 = 100
MIX2 = -100

You should see this in the input monitor, not in the channel monitor. The selected switch position is +100%, the others are -100%.
What you see in the channel monitor is the output of the mixers. Look inside to see what is done with the mix switch (inverted or similar is my guess).

Sorry for being imprecise:
Data given was on the "stick input" page of the channel monitor. Not on the channel output page, of course.