I feel like I am going nuts..
Issue, aRGB strips acting in parallel rather than series, both hooked up with adapters to corsair headers. Tested on both versions of the Splitty4.

No matter how I define RGB controllers in Aquasuite, the settings just mimic across both. I just feel like I'm missing a config or something. Any help would be appreciated.

I have a similar setup in a system with 3x corsair ML120 rgb fans and an argb strip built into the Lian Li PC-O11XL with corsair 4 pin adapter and everything behaves as expected. I have the 3 fans set up as one block of 12 leds and the strip as another block of 28 leds. I can control them as I see fit.

Setup:

D5 NEXT with aquabus connector and rgbpx connector into splitty4
Aquacomputer 53270 RGBpx 30 aRGB strip plugged into aquacomputer RGBpx cable to aquacomputer adapter 53285 to corsair 4-pin adapter
Heatkiller size M addressable RGB strip with adapter to corsair 4-pin
Specifications:
Voltage: 5V
Connector: 3-Pin (5VDG, 5V)
LED: 21x SMD RGB