I have the same problem, if the bulb is toggled directly then there is no flashing and the work that InuSasha did works perfectly. But if the bulb is part of a group then the flashing bulb problem still occurs. Editing homeassistant/components/hue/light.py lines 361 and 362 to comment them out as per tiger42’s instructions (different line numbers for some reason) has worked.
@InuSasha is there anything that can be done for Innr lights when they are part of a group?