WS2811 24V single color strip

I bought a ws2811 24V warmwhite only strip https://de.aliexpress.com/item/1005004776002909.html
as a staircase light. Every 2411 controls three LED in the RGB order. For testing I tried addressing the individual LEDs. This works fine if I configure the strings as WS2411 white and having just three leds. Via a segment config I’m able to control every LED on it’s own. (Having three segments). If I extend my LED config now, segment0 (from 0 to 1) controls the first LED of the first three ws2411 together.
If I configure just three LEDs skipping the first 1 I can control each LED of the the second ws2411) and so on.
Is this intended or a bug? Can this be changed or reconfigured?