Here are screen shots from MidOX (which I have never used before). Let me know if there is something specific you want to see.
This shows right after selecting a preset, then pressing the IA for Chorus 1 Channel (which turns it off, it is on by default) followed by selecting scene 6:
View attachment 48033
Here is a shot of selecting scenes 1-6 in sequence:
View attachment 48034
As you can see, there is NO additional or unexpected midi data being sent. Each line is a single click of a single scene IA in sequence from 1-6.
I am using CC# 34 for scenes and CC# 6 for Chorus 1 Channel as can be seen in the sysex output.
Doesn't make sense. Selecting a channel does not turn an effect on or off. I suspect you have bypass also mapped to CC #6.