I dunno. Using twisted pair for your rs485 wiring? Gnd connected at the first led and not at power supply. I think I was told this matters. I don’t see 1 strip of lights pulling gnd too high unless your power wiring is...
I found my detent stability point on the rotary encoder I purchased always gave gnd on a and b channels.
The pulses would only appear between the indents. I thought maybe this was normal as some sort of mechanical...