These are chat archives for Makuna/NeoPixelBus
@kopierschnitte Still having issues with random colours showing up within the first 10 pixels from time to time (making them dirty helps!) and inability to change pixel state for pixels 100+ after the strip is fully lit for a while.
The first pixels misbehaving could be a sign of cross-talk or static build-up where at the beginning of transmission the shape of pulses gets distorted enough to cause corruption until the line stabilizes. But this usually also results in pixel-shift, so I'm not sure it is what happens in your case too. Putting a ferrite core on the data line, or altering the timing a bit (as @Makuna suggested above) might help.
The 100+ pixel issue points to either a bug in your code, or a fault in the strip/leds itself. Could be a bad solder joint on LED # 100/101 D-out/D-in, which after a certain temperature is reached loses contact - so carefully resoldering those two pads might help. Or it could be a cracked/broken trace on the strip. Or even one of the two LEDs being faulty. All other causes are significantly less likely.