PWM channel 1 doesn't respond to either static rpm or percentage but does respond to a curve. Changed to channel 2 and all works fine. Like the OP the RPM seems kind of locked so even in a curve it's simply powering them on and off rather than actual PWM control.
I'm probably one of the few who does need all 6 channels (I have radiators grouped, mb fans, case fan zones etc) so I'd prefer it sorted sooner than later.
Running latest iCue and firmware I should have added.
Also could someone from Corsair (if you read this) please ask the pre sales team to answer messages- I have one on the ML series fans about their actual output before I buy any or go with better fans and use some diy fab 5v fan frames (they work out of the box as tested some yesterday)
