TK95

Just a quick one. I have a 2012 A6 AVANT C7, and every time I drive to and from london, on the M3, my MMI begins turn off and on constantly, at cycles of about 30 seconds. The strange thing about this, is it only occurs between the M25 and when I get to the end of the variable speed limit zone of the M3, and vice versa when I'm driving into London. Has this happened to anyone else, or any idea of what could be causing it? Cheers