Well, considering this post has had several views and no responses, I take it to mean that no one else has experienced this particular problem with the aftertouch . . . which is great news! Happy to see that it does not seem to be a common problem.
I must say that the Arturia team has been absolutely outstanding in helping me to get this problem resolved within the warranty period. A representative initially provided me with instructions for opening the left hand controller section to see if reseating the aftertouch ribbon cable would rectify the problem. Unfortunately, it did not, so I was required to send the unit for service. However, the Arturia team has done everything they can to make the process painless, and I should have the Matrixbrute back and functional within a week. Everyone I have been in correspondence with, both here in the US and abroad, has been above and beyond helpful. Thanks Arturia!
