I have a similar issue, when it is doing anything with shifting colors it is super obvious it is flickering or randomly restarting. Even with static colors I occasionally see a fan turn off an LED and then turn it back on (and an LED strip also fully turns off occasionally when set to static, if it is animating it has the same loop bug as the fans). I feel like it got worse recently (not sure if this is due to some bug in the iCue software), as I hadn't really noticed anything like this and then suddenly it was terrible and happened all the time.
My setup is 6 LL fans and 4 RGB LED lighting strips hooked through a combination of a single Lighting Node Pro and a Commander PRO.