Playing around with the Thunder Overlay is great fun!
When pressing several pads at the same time it easily happens that a pad doesn’t seem to send midi. In this case I can move the finger around, neither CC nor pitch bend is sent either. When lifting and retouching the surface then it usually works. Have looked at the MIDI stream to be sure it’s not my synth.
Looks like a small bug?
Otherwise - very nice!
Edit: Found a way to reproduce it 100% of the time: First Press P hard, leave the finger on it and additionally press 6 with a light touch. 6 won’t make any sound.