Korg Monologue, crazy MIDI behavior, HELP!

[809dao]

Hello everybody!

I've got quite an issue.
I'm starting to use the Monologue in a MIDI setup where it sends MIDI to a MPC 1000 which acts as a sequencer.
It worked fine for some days.
Now my Minilogue is starting to go crazy.
It started to thange programs randomly, respond randomly to keys (like pressing the same key multiple times will give different notes), get stuck notes, and make it generally unusable. On its own it works fine.

I've already tried the following:
Switching Local SW ON/OFF
Changing cables
Changing the input and ouput on the MPC (I have a MIDI merger and a MIDI splitter that I use, I thought they might be the problem, but overriding them and going directly into the MPC and out from the MPC didn't improve)
Playing notes from an external controller also provoked the same behavior

My drummachine (Roland TR-8) and volca keys work fine in the same setup. No stuck notes, no problems whatsoever.

Anyone experienced anything similar? Any suggestions?

Thanks a lot in advance. I really want to use the Monologue with a external sequencer so I can record more complex phrases...

Bogdan