Lane Departure switch fault

[BhxTrev]

Can anybody advise? If I activate the Lane Departure switch on the steering wheel of my Gen4 Prius Excel it activates but if I press the switch again to turn it off as according to the online manual, it doesn't work & remains activated. If I go into the menu display, choose the Lane Departure on the dash display & then press the Lane Departure button on thesteering wheel it then deactivates it. Does anyone know why I can't just toggle the Lane Departure switch on the steering wheel to turn this feature on & off? The software & maps are up to date so am I doing something wrong or could this be a software problem? 

[RelaxedDrive]

I seem to remember there was something a bit clunky with that switch, like if you pressed it again when it was on nothing came up on the LCD display to say it was off  - which is what I would have expected(but I guess the yellow/orange icon on the left of the dash should go out). 

Turning if off worked for me, but these days I always leave it on; it 'tells' my passengers when I'm getting tired!