Ok then, here is my post translated in english :
I was able to reproduce the problem with all types of after touch (AT, PolyAt, Mpe At) and using different controllers (hydrasynth keyboard, Launchpad pro mk3, linnstrument)
Here is my test session on reaper (I hope it suits you as a way to check, if not, tell me I'll send you the midi file separately)
https://www.dropbox.com/s/uko6c2hqvoui8fj/linnstrument%20debug.zip?dl=0Cordially
vincent
Edit:
Ah yes the sound is made like this:
It's init setting with 3 operators, Mix 1 to 0, all the values of the modulation matrix to 0 except the aftertouch (or poly or mpe...) modulating Mix1 with a factor of 1.00...