Re: Bosch SMS6012GB/20 Timer sticking.
Don’t think it anything to do with the timer. It could be the float sticking in the fill chamber (left hand side panel off for access) or the anti-flood switch activated ( if the metal base has water in it?) Also check that the black rubber sump hose is clear (they get gunged up with fat) and finally, the wiring loom that runs behind the door panel (the wires break as the door opens and closes.
But, no, don’t think it is a timer fault. 😀