Global Transpose only local Keyboard not on lower part

[Dingsdada]

Unfortunately I didn't find what I was looking for in the forum and someone can help me:
I play the sounds of my Electro 6D with an additional e-piano (External Keyboard to Lo), whose sound engine I want to use in parallel and layer sounds.
Since we transpose all songs to -1 in the band, I have to set both of my keyboards to -1.
Problem: My e-piano also sends the transposed signal at the Midi output and the Electro 6D then transposes it again, so that -2 is created together with -1 on the e-piano.

Is it possible to transpose only the upper-section so that the lower-part is not transposed twice?
Unfortunately, I cannot prevent this behavior on the e-piano (Roland FP-2) and the "transpose midi at..." setting on the electro has no effect here.

I am happy about every hint.
Best regards, Andreas

[maxpiano]

Hi, I am afraid there is no solution here other than using a MIDI processor in between (dedicated box or a computer/tablet to do the job)

If you were using the piano only as a master to trigger the NE6 Lower it would be enough to not transpose on it, but I guess it is not the case.