How frequently are you sending updates? The shipped firmware on Flotilla docks is a little sluggish and has been greatly improved since.
I'd highly recommend updating to the latest firmware in our pre-release repository here: https://github.com/pimoroni/flotilla-pre
Then use the latest Python API here: https://github.com/pimoroni/flotilla-python/tree/shipshape
There have been so many, many fixes that I couldn't possibly speculate on what might be broken in your setup! So onwards and upwards is the best way to go.
