Permanent Midi Through for specific midi controller

Hopefully some here can enlighten me here:

I have a midi controller (Korg nanokontrol) connected to the MPC (via BT or USB, same result).
I have an audio interface (ES-9) that can be controlled by midi, which is connected to the midi output port B of the MPC.

The midi from the nanokontrol is supposed to go through the MPC to the ES-9.
That works but ONLY when a midi track is currently selected that points to the respective midi out B of the MPC. As long as that track isn't in focus, nothing goes through.

So, the question is:
Is it possible to set up a midi controller to always get routed to the output of the MPC? Like a Midi Through kind of option?

Thanks in advance for any hints!

"...midi track is currently selected that points to the respective midi out..."

No midi through as far as I know. But somehow I like it that way. Even my old RS7000 worked that way - but was more difficult to enable/disable incoming midi data.

My favourite is to set
- Preferences > Sequencer > Rec Arm = "Multi" (alternatively press "Shift" and select the appropriate tracks in "Track View" - just a tic of more work)
- Track View (three bar icon) -> here you can arm the incoming data flow (external and internal) by activating all required instruments on-the-fly - even use it for life performance.
This will give you a maximum of control of what is coming in - and finaly going out
I use this for Virus Ti Multi voice and it is great, as I can switch on/off parts without touching the Virus.
(btw. works for recording of course too, as it was designed to do exactly that...)

I hope I covered the request for help....

I don't have access to my midi stuff ATM, but i've checked the manual and it seems that "IN" or "Merge" setting for MIDI track "Monitor" button might also be handy as it would not require track to be armed:

"When set to In, the track's MIDI input is always monitored regardless of the track's Record Arm state, and playback from recorded events will not be heard."
"When set to Merge, the track's MIDI input is always monitored, and playback of recorded events will be heard."

"..."IN" or "Merge" setting for MIDI track "Monitor" button might also be handy..."
yes, true. But to enable/disable it takes one or two more tapping

..and the "red eye" icon is more obvious than reading "in" or "merge" - "auto" is in this case my favourite. But it gives the option of what fits best.

edit: yes, if you have pre-recorded tracks it does not matter what you set the monitor to - except "in", which will cut off the recorded data.