Intermittent problems are the hardest to track down. 600 tracks here, FWIW, but I don’t use the controller to bank around it regularly so I may not be seeing the error (I use mix configs exclusively with it).
Consider checking out this thread. The midi remote here may work better for you (I can’t use it as I depend on visibility configs)
Track color script for Icon P1-X & D4 display - Cubase - Steinberg Forums