2nd hand Model 01 with QMK and lots of key-stutter

(I already did the alcohol cleaning method, and it did not help).
I bought it 2 weeks ago, but only yesterday started doing some typing, with a completely new layout (so I am VERY slow), and yet I see key-stutter quite a lot (one in 50 chars), on many different keys. It always works like this, when it happens: key gets stuck (as if held down), until one presses an other/the same key.
I wonder if this might be a firmware issue instead of a hardware one. I also have the key 1 not registering at all, and currently am failing to flash kaleidoscope back onto it for testing, but surely should do try to do that again!

Managed to get the example Kaleidoscope firmware flashed, and the Key_1 key is working there. now testing whether there will be shutter …

so far, no stutter after about 200 chars (I am very slow with the new layout)

… great! :slight_smile:
so my hardware is fine, but that means that the QMK settings/way of scanning keys is somehow causing key-stutter

I (seem to) recall that some debouncing algorithm was added/improved to Kaleidoscope after a while.

I would say that QMK is not causing the stuttering, as much that it is not masking that property of the keyswitches.