Try cleaning the discs with a flap sander or similar, the OE discs seems to deposit shit on them, I cleaned up my 1190 / 1290 discs and in both cases the pulsing went away.
Fitted SBS street pads to 1290 last year after it started doing it, hoping they don't do this, IME it seems to happen when they get real hot - like trips to Alps / Black Forest etc where there are a lot of more corners with few straights to let them cool.