Confirmed.
If Sports mode switch is ON toggling multiple flight mode menu option OFF causes the Multi Flight Mode Icon to appear, toggling it on causes it to disappear. If Sports mode is off then the Multiple Flight mode switch has no effect on the on the icon, it remains visible all the time.
I think we have simply or at least I have caused us to get the Multiple Flight Modes switch under the copter menu to be confused with Intelligent flight modes, I think this option only enables/disables Sports mode. So when the hardware Sports mode switch is on and you go into the menu and disable Multiple Flight Modes the Intelli Flight Modes icon appears because you have disabled Sports mode. It works correctly.