Problem with changing the midi channel

[mka73]

Hello
I have a problem with changing the midi channel for the local keyboard in the m3 korg. I have another keyboard connected to the korg via midi, which unfortunately only sends messages on the midi channel 1 and plays the sounds set on this channel in the korg. In korg, I changed the global midi channel to 2, but the korg keyboard still plays the sounds from channel 1 and additionally from channel 2, and I mean that it only plays sounds set on channel 2
Can anyone help me on this topic?

Best wishes
Marcin