>>This may be your pedal – if it is a little weak, you can hit it hard during calibration, which sets a limit. Then, later, unless you hit it equally hard, you may not be able to hit the same limit. Try calibrating very gently, and then turning calibration off.<<

The EV-5 used via stereo into the expression pedal in works perfectly. 

>>It will ignore the TIP of the switch, because you have told it you are using this for pedal.<<

I get mixed advice now – in the forums I read that it should be set to both, in the control app it mentions both should be used for Y-cables. EXPTIP on the device is the same setting that is in the control app named "Use Exp pedal, Aux switch or both" – IMO this should be set to both. 

>>Make sure that MIDI.CLK.OUT is ON.

CLK out is on, I'm using that already to use on of the H9 pedals as a master tempo to send the clock to another H9 and a Mobius.

Where I'm at now:

– I'm positive that my Y-cable works and is created correctly. 

– I'm connecting one of the mono cables of the Y-cable into the EV-5 which has a stereo IN. This stereo in of the EV-5 works when connecting it via a stereo cable into the H9 and into my Axe Fx II.  Does the H9 detect this correctly? I read that someone had this working with an EB volume pedal which is probably mono. Should I wire the potentiometer in the EV5 differently? It seems to not work correctly now because the EV-5 gets a mono cable.